ordered_options will work if inherited from Hash, remove OrderedHash usage

Bug: cache_key.size doesn't return length of filename but size of file

Refactored two methods to use delete with a block

suggested changes.

use Hash#delete on styelsheet_link_tag

Allow ActiveResource subclasses to inherit headers from parent

form option refactor

Closes #5025

Reset memoized hash keys when new ActionView::Template handler is registered
Conflicts:

	actionpack/lib/action_view/template/handlers.rb

assigns(:foo) should not convert @foo's keys to strings if it happens to be a hash

Restoring ability to derive id/sequence from tables with nonstandard sequences for primary keys

add selected and disabled options to grouped select

Restored ability to identify ID and Sequence from tables relying on a nonmatching sequence default value for PK.

AM::Errors: allow :full_messages parameter for #to_json

Windows doesn't allow `\ / : * ? " < > |` in filenames so create
the fixture files at runtime and ignore the incompatible ones when
running on Windows.

Update activerecord/CHANGELOG.md