Only accept actions without File::SEPARATOR in the name.

This will avoid directory traversal in implicit render.

Fixes: CVE-2014-0130
Preparing for 3.2.18 release
Fix broken tests of the previous release
Merge branch '3-2-sec' into 3-2-stable

Conflicts:
	actionpack/CHANGELOG.md
use fnmatch to test for case insensitive file systems

this is due to:

  https://bugs.ruby-lang.org/issues/5994
feature detect for FNM_EXTGLOB for older Ruby. Fixes #15053
Feature detect based on Ruby version.

I didn't want to do this, FNM_EXTGLOB is defined on 2.1.x, but Dir.glob
returns the wrong value on Ruby less than 2.2.0.  Checking for a
case-insensitive FS seems too hard, so just check Ruby version  Checking
for a case-insensitive FS seems too hard, so just check Ruby version.
File.exists? is a deprecated name, use File.exist?

File.exists? is a deprecated name, use File.exist?
Merge pull request #15794 from vishalzambre/patch-1

File.exists? is a deprecated name, use File.exist?
Revert "Merge pull request #15794 from vishalzambre/patch-1"

This reverts commit 6d800a909e24465ca6f3fa5206222fa7d78967f6, reversing
changes made to 6a051299f98ee43864326c6c0a4f7d169d22b3f8.

We don't apply non-security fixes to 3-2-stable branch!!!
Add nohidden option to check_box helpers to suppress hidden field when necessary
Fix Memoizable#prime_cache for private and protected methods

Matches change made in commit cc3183d4bec6855b9b5931759a22dd228dfe7687 for flushing cache.
Return a 405 response for unknown HTTP methods

Conflicts:
	actionpack/CHANGELOG.md
	actionpack/test/dispatch/debug_exceptions_test.rb