[Testing guide] Use "Fixtures API" instead of "fixture api".
[Testing guide] Using "Fixtures API" consistently

- In guides, "API" is used consistently instead of "api".
- Reason behind replacing "fixtures API" to "Fixtures API" is because
  here we are referring to the concept of "fixtures". In other places in
  the guide "fixture" OR "fixtures" is referred to the single or
  multiple instances of test data.
- This is also followup of https://github.com/rails/docrails/commit/aa9d1332b20305dd860b21a7ada06c5252bebad5#commitcomment-8497376.
Fix grammar on ActiveRecord::AttributeMethods doc.

[ci skip]
allow 'all' for :domain option in addition to :all
Don't remove mailer layouts files
Remove custom errors page section from the guides

This pattern is too problematic and introduces a lot of edge cases:

  * On 4.2, the issue https://github.com/rails/rails/issues/15124 is
    back again.
  * needs to define each action for each http status otherwise the
    router raises ActionController::RoutingError (No route matches).
  * If the router has `match "/*username",...` and some action is
    missing, Rails will pick up the "match" and try to do its job.
  * encourages people to copy & paste programming. Not DRY.

[ci skip]
Fix Sidekiq ActiveJob integration setup

* .connect on a Redis connection wasn't valid
* Reset logger after we're done testing for redis connection to avoid
  "closed stream" error when starting server for real from a fork
Hide potentially sensitive ActiveJob params from logs

* Show GlobalID instead of full object .inspect output
Merge branch 'master' of github.com:rails/rails
Only filter GIDable objects; remove cosmetic changes
fixing mailer previews for apps with globbing route
Clarify that batching methods can be used with any orderable type primary key, not just integer ones, as per @a58cafeb3a86be46849de57481b6644094fb8165
Prevent Symbol GC
Add documentation to MessageVerifier

[ci skip]

Complements #17727 and closes ee73d9ff8.

@lleger How do you feel about this?
Remove "rescue" clause around "require 'openssl'"

Some `require 'openssl'` statements were surrounded by `rescue` blocks to deal with Ruby versions that did not support `OpenSSL::Digest::SHA1` or `OpenSSL::PKCS5`.

[As @jeremy explains](https://github.com/rails/rails/commit/a6a0904fcb12b876469c48b1c885aadafe9188cf#commitcomment-8826666) in the original commit:

> If jruby didn't have jruby-openssl gem, the require wouldn't work. Not sure whether either of these are still relevant today.

According to the [release notes for JRuby 1.7.13](http://www.jruby.org/2014/06/24/jruby-1-7-13.html):

> jruby-openssl 0.9.5 bundled

which means the above `rescue` block is not needed anymore.

All the Ruby versions supported by the current version of Rails provide those OpenSSL libraries, so Travis CI should also be happy by removing the `rescue` blocks.

---

Just to confirm, with JRuby:

    $ ruby --version #=> jruby 1.7.16.1 (1.9.3p392) 2014-10-28 4e93f31 on Java HotSpot(TM) 64-Bit Server VM 1.8.0_20-b26 +jit [darwin-x86_64]
    $ irb
    irb(main):001:0> require 'openssl' #=> true
    irb(main):002:0> OpenSSL::Digest::SHA1 #=> OpenSSL::Digest::SHA1
    irb(main):003:0> OpenSSL::PKCS5 # => OpenSSL::PKCS5

And with Ruby 2.1:

    $ ruby --version #=> ruby 2.1.2p95 (2014-05-08 revision 45877) [x86_64-darwin13.0]
    $ irb
    irb(main):001:0> require 'openssl' #=> true
    irb(main):002:0> OpenSSL::Digest::SHA1 #=> OpenSSL::Digest::SHA1
    irb(main):003:0> OpenSSL::PKCS5 #=> OpenSSL::PKCS5
Merge pull request #17901 from isaacseymour/fix-find-each-docs

Correct docs for ActiveRecord batching methods [ci skip]
docs, bring back `ActiveRecord::Core` methods in the API. [ci skip]

This `# :nodoc:` had the effect of hiding every method that follows.
This meant that the API page for `ActiveRecord::Core` only contained
`configurations` and none of the following methods.

Furthermore this `# :nodoc:` had no effect on `maintain_test_schema`.
Those `mattr_accessor` inside the `included` block are not picked up
by rdoc.

/cc @zzak
Merge pull request #17903 from claudiob/remove-rescue-openssl

Remove "rescue" clause around "require 'openssl'"
remove misleading class [ci skip]
remove unused #await_close

The method was added in https://github.com/rails/rails/commit/30d21dfcb7fafe49b3805b8249454485a90097b6#diff-5055d9f16b442adb1d2f0f65903a196bR141.
With the method call in https://github.com/rails/rails/commit/30d21dfcb7fafe49b3805b8249454485a90097b6#diff-cc7bb557df2247c0a42bc180fdb6eb05R47.
Later one more method call was added in https://github.com/rails/rails/commit/401787db4bc428dce88b04e343a64c6a6c3b681c#diff-cc7bb557df2247c0a42bc180fdb6eb05R183.
And both method calls were deleted in https://github.com/rails/rails/commit/3df07d093a1e4207caa63fd2e3b67599211f5800#diff-cc7bb557df2247c0a42bc180fdb6eb05L47 and https://github.com/rails/rails/commit/3df07d093a1e4207caa63fd2e3b67599211f5800#diff-cc7bb557df2247c0a42bc180fdb6eb05L189.

Just do `grep -nr 'await_close' .`.