Squashed commit of the following:

commit 2683de5da85135e8d9fe48593ff6167db9d64b18
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Fri May 3 11:29:20 2013 -0700

    cannot support infinite ranges right now

commit cebb6acef2c3957f975f6db4afd849e535126253
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Fri May 3 11:26:12 2013 -0700

    reverting infinity comparison

commit 385f7e6b4efd1bf9b89e8d607fcb13e5b03737ea
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Fri May 3 11:23:28 2013 -0700

    Revert "Added ability to compare date/time with infinity"

    This reverts commit 38f28dca3aa16efd6cc3af6453f2e6b9e9655ec1.

    Conflicts:
    	activesupport/CHANGELOG.md
    	activesupport/lib/active_support/core_ext/numeric/infinite_comparable.rb
    	activesupport/test/core_ext/date_ext_test.rb
    	activesupport/test/core_ext/date_time_ext_test.rb
    	activesupport/test/core_ext/numeric_ext_test.rb
    	activesupport/test/core_ext/time_ext_test.rb
    	activesupport/test/core_ext/time_with_zone_test.rb

commit 0d799a188dc12b18267fc8421675729917610047
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Fri May 3 11:18:53 2013 -0700

    Revert "Refactor infinite comparable definition a bit"

    This reverts commit dd3360e05e4909f2f0c74a624cccc2def688f828.

commit 42dec90e49745bbfae546f0560b8783f6b48b074
Author: Aaron Patterson <aaron.patterson@gmail.com>
Date:   Fri May 3 11:18:47 2013 -0700

    Revert "Require 'active_support/core_ext/module/aliasing' in the infinite_comparable module"

    This reverts commit 7003e71c13c53ec3d34250560fbf80b8381df693.

10 files changed, 7 insertions, 63 deletions

diff --git a/activesupport/lib/active_support/core_ext/date.rb b/activesupport/lib/active_support/core_ext/date.rb
index 5f13f5f70f..465fedda80 100644
--- a/activesupport/lib/active_support/core_ext/date.rb
+++ b/activesupport/lib/active_support/core_ext/date.rb
@@ -2,5 +2,4 @@ require 'active_support/core_ext/date/acts_like'
 require 'active_support/core_ext/date/calculations'
 require 'active_support/core_ext/date/conversions'
 require 'active_support/core_ext/date/zones'
-require 'active_support/core_ext/date/infinite_comparable'
 
diff --git a/activesupport/lib/active_support/core_ext/date/infinite_comparable.rb b/activesupport/lib/active_support/core_ext/date/infinite_comparable.rb
deleted file mode 100644
index ca5d793942..0000000000
--- a/activesupport/lib/active_support/core_ext/date/infinite_comparable.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-require 'active_support/core_ext/infinite_comparable'
-
-class Date
-  include InfiniteComparable
-end
diff --git a/activesupport/lib/active_support/core_ext/date_time.rb b/activesupport/lib/active_support/core_ext/date_time.rb
index 024af91738..e8a27b9f38 100644
--- a/activesupport/lib/active_support/core_ext/date_time.rb
+++ b/activesupport/lib/active_support/core_ext/date_time.rb
@@ -2,4 +2,3 @@ require 'active_support/core_ext/date_time/acts_like'
 require 'active_support/core_ext/date_time/calculations'
 require 'active_support/core_ext/date_time/conversions'
 require 'active_support/core_ext/date_time/zones'
-require 'active_support/core_ext/date_time/infinite_comparable'
diff --git a/activesupport/lib/active_support/core_ext/date_time/calculations.rb b/activesupport/lib/active_support/core_ext/date_time/calculations.rb
index f347f09293..937567440b 100644
--- a/activesupport/lib/active_support/core_ext/date_time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date_time/calculations.rb
@@ -155,4 +155,11 @@ class DateTime
   def utc_offset
     (offset * 86400).to_i
   end
+
+  # Layers additional behavior on DateTime#<=> so that Time and
+  # ActiveSupport::TimeWithZone instances can be compared with a DateTime.
+  def <=>(other)
+    super other.to_datetime
+  end
+
 end
diff --git a/activesupport/lib/active_support/core_ext/date_time/infinite_comparable.rb b/activesupport/lib/active_support/core_ext/date_time/infinite_comparable.rb
deleted file mode 100644
index 8a282b19f2..0000000000
--- a/activesupport/lib/active_support/core_ext/date_time/infinite_comparable.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-require 'active_support/core_ext/infinite_comparable'
-
-class DateTime
-  include InfiniteComparable
-end
diff --git a/activesupport/lib/active_support/core_ext/infinite_comparable.rb b/activesupport/lib/active_support/core_ext/infinite_comparable.rb
deleted file mode 100644
index b78b2deaad..0000000000
--- a/activesupport/lib/active_support/core_ext/infinite_comparable.rb
+++ /dev/null
@@ -1,35 +0,0 @@
-require 'active_support/concern'
-require 'active_support/core_ext/module/aliasing'
-require 'active_support/core_ext/object/try'
-
-module InfiniteComparable
-  extend ActiveSupport::Concern
-
-  included do
-    alias_method_chain :<=>, :infinity
-  end
-
-  define_method :'<=>_with_infinity' do |other|
-    if other.class == self.class
-      public_send :'<=>_without_infinity', other
-    else
-      infinite = try(:infinite?)
-      other_infinite = other.try(:infinite?)
-
-      # inf <=> inf
-      if infinite && other_infinite
-        infinite <=> other_infinite
-      # not_inf <=> inf
-      elsif other_infinite
-        -other_infinite
-      # inf <=> not_inf
-      elsif infinite
-        infinite
-      else
-        conversion = "to_#{self.class.name.downcase}"
-        other = other.public_send(conversion) if other.respond_to?(conversion)
-        public_send :'<=>_without_infinity', other
-      end
-    end
-  end
-end
diff --git a/activesupport/lib/active_support/core_ext/numeric.rb b/activesupport/lib/active_support/core_ext/numeric.rb
index d5cfc2ece4..a6bc0624be 100644
--- a/activesupport/lib/active_support/core_ext/numeric.rb
+++ b/activesupport/lib/active_support/core_ext/numeric.rb
@@ -1,4 +1,3 @@
 require 'active_support/core_ext/numeric/bytes'
 require 'active_support/core_ext/numeric/time'
 require 'active_support/core_ext/numeric/conversions'
-require 'active_support/core_ext/numeric/infinite_comparable'
diff --git a/activesupport/lib/active_support/core_ext/numeric/infinite_comparable.rb b/activesupport/lib/active_support/core_ext/numeric/infinite_comparable.rb
deleted file mode 100644
index b5f1b0487b..0000000000
--- a/activesupport/lib/active_support/core_ext/numeric/infinite_comparable.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-require 'active_support/core_ext/infinite_comparable'
-
-class Float
-  include InfiniteComparable
-end
-
-class BigDecimal
-  include InfiniteComparable
-end
diff --git a/activesupport/lib/active_support/core_ext/time.rb b/activesupport/lib/active_support/core_ext/time.rb
index af6b589b71..32cffe237d 100644
--- a/activesupport/lib/active_support/core_ext/time.rb
+++ b/activesupport/lib/active_support/core_ext/time.rb
@@ -3,4 +3,3 @@ require 'active_support/core_ext/time/calculations'
 require 'active_support/core_ext/time/conversions'
 require 'active_support/core_ext/time/marshal'
 require 'active_support/core_ext/time/zones'
-require 'active_support/core_ext/time/infinite_comparable'
diff --git a/activesupport/lib/active_support/core_ext/time/infinite_comparable.rb b/activesupport/lib/active_support/core_ext/time/infinite_comparable.rb
deleted file mode 100644
index 63795885f5..0000000000
--- a/activesupport/lib/active_support/core_ext/time/infinite_comparable.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-require 'active_support/core_ext/infinite_comparable'
-
-class Time
-  include InfiniteComparable
-end