Improve ERB dependency detection.

The current implementation can't handle some special cases of oddly-formatted Ruby. Now we are able to detect them:

* Multi-line arguments on the `render` call
* Strings containing quotes, e.g. `"something's wrong"`
* Multiple kinds of identifiers - instance variables, class variables and globals
* Method chains as arguments for the `render` call

Also, this fix reduces the rate of "false positives" which showed up when we had calls/access to identifiers containing `render`, like `surrender` and `rendering`.
Avoid scanning multiple render calls as a single match.

Each chunk of text coming after `render` is now handled individually as a possible list of arguments.
Update changelog
Add failing test for #13369

After introducing 50311f1 a regression was introduced: routes with
trailing slash are no longer recognized properly. This commit provides a
failing test for this situation.
Revert "Don't remove trailing slash from PATH_INFO for mounted apps"

The revert is needed because of a regression described in #13369, routes
with trailing slash are no longer recognized properly.

This reverts commit 50311f1391ddd8e0349d74eb57f04b7e0045a27d.
Revert "methods are defined right after the module_eval, so we don't need to do"

This change breaks tests in activesupport/test/core_ext/module_test.rb:

* test_delegation_exception_backtrace
* test_delegation_exception_backtrace_with_allow_nil

This reverts commit 0167765e3f84260522bc2f32d926c1f5dd44957c.
Fix test for cache_key + touched

Ensure the child can actually be touched. The `Bulb` model has no
timestamp column, thus trying to touch it would return `nil`.
Make AR::Base#touch fire the after_commit and after_rollback callbacks
Merge branch 'ca-touch-commit-callbacks'

Make AR::Base#touch fire the after_commit and after_rollback callbacks.

Closes #12031.
define the delegate methods on one line. fixes #13724

sup haters
Update deprecation warning to give more information about caller
Merge pull request #13734 from tjschuck/fixture_class_name_deprecation_warning

Update fixture class name deprecation warning to give more information about caller
No need to use #send with public methods
Cleanup duplicated setup of callbacks in transactions tests
No need for instance vars on single tests
Do not set up a variable used only in two tests

Just create a local variable whenever we need the record, rather than
doing an extra find for every test on the setup method.
Move AR test classes inside the test case
Use minitest's skip rather than conditionals + early returns
Extract a method to simplify setup code
Merge pull request #13414 from britto/jb-fix-dependency-matching

Improve ERB dependency detection