Added some missing activesupport test coverage

Remove not-required file class/subclasses

Touch option description grammatical error fixed [ci skip]

Generators guide grammatical error fixed [ci skip]

[ci skip] Fix code in Routing Guide

Conflicts:
	actionpack/test/abstract_unit.rb

We are planning to remove mocha from our test suite because of
performance problems. To make this possible we should stop require mocha
on ActionSupport::TestCase.

This should not affect applications since users still need to add mocha
to Gemfile and this already load mocha.

Added FIXME notes to place that still need mocha removal

Missing test for form values before type cast

Some ActionView renderer refactors

Fixed typo in comment [ci skip]

Make create_join_table use the same logic as HABTM reflections

Fixes to request method test.

Additional help messaging to help the user resolve a conflicted migration

Cleanup + CHANGELOG for pr #14886

Also cleanup test a bit

[related #14886]
[related #14743]

The entire 127.0.0.0/8 range is assigned to the loopback address, not
only 127.0.0.0/24. This patch allows ActionDispatch::Request::LOCALHOST
to match any IPv4 127.0.0.0/8 loopback address.

The only place that the #local? method was previously under test was
in the show_expectations_test.rb file. I don't particularly like that
that's implicitly where this code is under test, and I feel like I
should move some of that testing code into the
test/dispatch/request_test.rb file, but I wanted some feedback first.

Credit goes to @sriedel for discovering the issue and adding the
patch.

Before this change, create_join_table would not remove the common prefix
in the join table name, unlike ActiveRecord::Reflections. A HABTM
between Music::Artist and Music::Record would use a table
music_artists_records, while create_join table would create
music_artists_music_records.

Dont swallow errors when bad alias_method

Even if this is not exactly the same, let's add a new-line character
instead of two spaces. While it's specified in the Markdown specs that
adding spaces at the end of the line creates a break-line tag, this is
a brittle approach as people may remove them saving the file on certain
editors.

Prefer to pass block when logging.

The Logger by default includes a guard which checks for the
logging level. By removing the custom logging guards, we can decouple
the logging guard from the logging action to be done.

This also follows the good practice listed on http://guides.rubyonrails.org/debugging_rails_applications.html#impact-of-logs-on-performance.

Since we're stubbing the request, the test is actually just asserting
that `@method = env['REQUEST_METHOD']`. In order to the test against
the methodoverride middleware, we should test it against an actual
request. However, Rack is already covering this scenario so we can
remove this test.

There is already another test covering Request#request_method. This
test should cover Request#method.

The current test is asserting against an outdated version of
Request#method where HEAD requests are treated as GET requests.

Added additional help messaging when there's scaffolding being generated and a migration already exists for the resource.

The user is now alerted that they are able to skip the conflicted migration file via the --skip option.

(I think)