Added test to ensure that DescendantsTracker does not leak memory on singleton classes
Change ActionController::Parameters#require behavior when value is empty
When the value for the required key is empty an ActionController::ParameterMissing is raised which gets caught by ActionController::Base and turned into a 400 Bad Request reply with a message in the body saying the key is missing, which is misleading.

With these changes, ActionController::EmptyParameter will be raised which ActionController::Base will catch and turn into a 400 Bad Request reply with a message in the body saying the key value is empty.
Fixed a bug in  when using has_many association with :inverse_of option and UUID primary key.
DirtyModel uses a hash to keep track of any changes made to attributes
of an instance. When using the attribute_will_change! method, you must
supply a string and not a symbol or the *_changed? method will break
(because it is looking for the attribute name as a string in the keys
of the underlying hash). To remedy this, I simply made the underlying
hash a HashWithIndifferentAccess so it won't matter if you supply
the attribute name as a symbol or string to attribute_will_change!.
make sure both headers are set before checking for ip spoofing
Adding documentation to +polymorphic_url+
concerning the options that it inherits from +url_for+. The way that
+polymorhpic_url+ is built allows it to have options
like +:anchor+, +:script_name+, etc. but this is currently not
documented.
Improve the testing guide [ci skip]

Improve the "Testing Rails Applications" guide adding a section for
testing helpers and a little note about associations with ActiveRecord
and YAML fixtures.

Also add a link to Fixture Builder ; yet another replacement for
fixtures such as Machinist or FactoryGirl.
Fix doc in Postgres database creation
Raising an error when nil or non-hash is passed to update_attributes.
Remove conditional, since results are always an instance of `ActiveRecord::Result`
Fix typo.
Migration dump UUID default functions to schema.rb. Fixes #10751.
Update the filestore documentation for clear
[ci skip]
Add documentation for #clear on certain Store classes
[ci skip
Add documentation for FileStore#increment and #decrement
[ci skip]
Array#to_formatted_s does not call each element's to_s anymore

Array#to_s calls each element's inspect since ruby 1.9
Remove ambiguity with pluralizations and I18n keys used for association restrict_dependent_destroy errors
Using ruby 1.9 syntax [ci skip]
Rack Sendfile is coming as default now
Added Rack::Sendfile in rake about [ci skip]