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.
Remove unnecessary require from active_support/inflector/methods.rb

`active_support/inflections` already requires
`active_support/inflector/inflections`. There's no need to require it in
`active_support/inflector/methods`.
change to destructive `deep_symbolize_keys` after https://github.com/rails/rails/commit/df24b8790f22384a068fece7042f04ffd2fcb33e which allows to do so. This helps to avoid extra hash object creation, by symbolizing inplace
make "rails dbconsole" work with activerecord-postgis-adapter
Add test for AR::CounterCache.update_counters
Refactor AR's counter_cache_test.rb test
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!.
Use Range#cover? for Numeric ranges (tests via endpoints) and use Range#include? for non-numeric ranges

added changelog message
make sure both headers are set before checking for ip spoofing
Remove OracleDatabaseTasks was deprecated, because this was provided by 3rd-party.
Remove SqlseverDatabaseTasks was deprecated, because this was provided by 3rd-party.
Remove FirebirdDatabaseTasks was deprecated, because this was provided by 3rd-party.
Added a warning about #1769 to the routing guide.
Use symbols instead of strings

ActiveSupport::Concern is used all over Rails
This PR will only create 3 new objects as keys are never recreated and
are not subject to garbage collection.

The strings were being uniquely created and garbage collected. I don't
have any performance numbers but this should be better than all of the
GC.
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.
Merge pull request #142 from codyrobbins/master

Added a warning about #1769 to the routing guide
more guidelines for command line
`existant` => `existent`