Fix #4979 against 3-2-stable - delete_all raise an error if a limit is provided
Make sure that javascript_include_tag/stylesheet_link_tag methods in
sprockets/helpers/rails_helper.rb discard duplicated assets
Add a role option to wrap_parameters.

The role option identifies which parameters are accessible and should be wrapped. The default role is :default.
improvements in "caching_with_rails" guide - backported from docrails

Conflicts:

	railties/guides/source/caching_with_rails.textile
Merge pull request #6158 from Dagnan/3-2-stable

improvements in "caching_with_rails" guide
added beginning_of_hour support to core_ext calculations for Time and DateTime
Merge pull request #4445 from nragaz/role_based_params_wrapping

specify a role for identifying accessible attributes when wrapping params
Merge pull request #6128 from frodsan/delete_all_limit_32

Fix #4979 against 3-2-stable
Give more detailed instructions in script/rails in engine

closes #4894
Merge pull request #6170 from mjtko/feature-beginning_of_hour-for-3-2-stable

Backport beginning and end of hour support for Time and DateTime to 3-2-stable
Add failing test re #3436 which demonstrates content_type is not respected when using the :head method/shortcut
If content_type is explicitly passed to the :head method use the value or fallback
Merge pull request #6198 from whistlerbrk/3-2-stable

Address ActionPack head method not respecting explicitly set content-type #3436
locking ruby-prof until we got a fix
Merge pull request #6200 from arunagw/3-2-stable

locking ruby-prof for now.
added docs to attribute_accessors methods
Merge pull request #6211 from frodsan/docs_attr_accessor_32stable

Adding docs to attribute accessor methods.
removing docs duplication
Merge pull request #6213 from frodsan/cut_docs_dup

Removing attribute_accessor docs duplication
Fix build