Squashed commit of the following:

commit a88875ac6abaa4d8116b42af8cd71189ce3d44d3
Author: Siddharth Bhatore <sbhatore95@gmail.com>
Date:   Thu Apr 23 12:26:08 2015 +0530

    [ci skip] Update doc fix cookies

commit f175eaa7a21db898fc6c66334f770831028f9d00
Author: Siddharth Bhatore <sbhatore95@gmail.com>
Date:   Mon Apr 20 12:58:04 2015 +0530

    Description inside Signed and Encrypted CookieJars added

1 files changed, 8 insertions, 0 deletions

diff --git a/actionpack/lib/action_dispatch/middleware/cookies.rb b/actionpack/lib/action_dispatch/middleware/cookies.rb
index b7687ca100..0ef1dd3ae5 100644
--- a/actionpack/lib/action_dispatch/middleware/cookies.rb
+++ b/actionpack/lib/action_dispatch/middleware/cookies.rb
@@ -454,12 +454,16 @@ module ActionDispatch
         @verifier = ActiveSupport::MessageVerifier.new(secret, digest: digest, serializer: ActiveSupport::MessageEncryptor::NullSerializer)
       end
 
+      # Returns the value of the cookie by +name+ if it is untampered,
+      # returns +nil+ otherwise or if no such cookie exists.
       def [](name)
         if signed_message = @parent_jar[name]
           deserialize name, verify(signed_message)
         end
       end
 
+      # Signs and Sets the cookie named +name+. The second argument may be the cookie's
+      # value or a hash of options as documented above.
       def []=(name, options)
         if options.is_a?(Hash)
           options.symbolize_keys!
@@ -511,12 +515,16 @@ module ActionDispatch
         @encryptor = ActiveSupport::MessageEncryptor.new(secret, sign_secret, digest: digest, serializer: ActiveSupport::MessageEncryptor::NullSerializer)
       end
 
+      # Returns the value of the cookie by +name+ if it is untampered,
+      # returns +nil+ otherwise or if no such cookie exists.
       def [](name)
         if encrypted_message = @parent_jar[name]
           deserialize name, decrypt_and_verify(encrypted_message)
         end
       end
 
+      # Encrypts and Sets the cookie named +name+. The second argument may be the cookie's
+      # value or a hash of options as documented above.
       def []=(name, options)
         if options.is_a?(Hash)
           options.symbolize_keys!