Calling ActiveSupport::TestCase.i_suck_and_my_tests_are_order_dependent! in AS::TestCase makes
everyone's tests order dependent, which should never be done by the framework.

So this trick is not needed to be documented anymore.

The message passed to Minitest's assert_raise is used as output in case
the assertion fails, but we can test against the exact message by using
the actual exception object that is returned from the assert_raise call.

just ask whether or not the route is defined

Email does not support relative links since there is no implicit host. Therefore all links inside of emails must be fully qualified URLs. All path helpers are now deprecated. When removed, the error will give early indication to developers to use `*_url` methods instead.

Currently if a developer uses a `*_path` helper, their tests and `mail_view` will not catch the mistake. The only way to see the error is by sending emails in production. Preventing sending out emails with non-working path's is the desired end goal of this PR.

Currently path helpers are mixed-in to controllers (the ActionMailer::Base acts as a controller). All `*_url` and `*_path` helpers are made available through the same module. This PR separates this behavior into two modules so we can extend the `*_path` methods to add a Deprecation to them. Once deprecated we can use this same area to raise a NoMethodError and add an informative message directing the developer to use `*_url` instead.

The module with warnings is only mixed in when a controller returns false from the newly added `supports_relative_path?`.

Paired @sgrif & @schneems

[ci skip]

This fixes the broken code block rendering and indents the examples
within the parameter list.

Fix that render layout should also be picked up by the template dependency tracker, but only half-ways. You can add that layout option on the same render call, and both templates should be added to the dependency tree. But thats going to require a more serious rework of the tracker. Please do help fix this part of it too. For now, render layout needs to be on its own line.

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

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.

[Jonas Baumann & Yves Senn]

The submitted params from a select with `multiple: true` look as follows:

```
{post: {category: [""]}}

{post: {category: ["", "Category 1", "Category 2"]}}
```

This is a follow up to #1552.

The performance is almost the same with both implementations but this is
clear.

Before this patch:

Calculating -------------------------------------
  small erb template      1452 i/100ms
-------------------------------------------------
  small erb template    17462.1 (±13.3%) i/s -      85668 in   5.031395s
.Calculating -------------------------------------
small erb template with 1 partial
                           887 i/100ms
-------------------------------------------------
small erb template with 1 partial
                         8899.6 (±18.8%) i/s -      42576 in   5.009453s
.Calculating -------------------------------------
small erb template with 2 partials
                           666 i/100ms
-------------------------------------------------
small erb template with 2 partials
                         6821.5 (±8.8%) i/s -      33966 in   5.020791s

After the patch:

Calculating -------------------------------------
  small erb template      1479 i/100ms
-------------------------------------------------
  small erb template    15956.6 (±7.6%) i/s -      79866 in   5.036001s
.Calculating -------------------------------------
small erb template with 1 partial
                           841 i/100ms
-------------------------------------------------
small erb template with 1 partial
                         9242.2 (±6.9%) i/s -      46255 in   5.029497s
.Calculating -------------------------------------
small erb template with 2 partials
                           615 i/100ms
-------------------------------------------------
small erb template with 2 partials
                         6524.7 (±6.8%) i/s -      32595 in   5.020456s

You can find the benchmark code at
https://gist.github.com/rafaelfranca/dee31120cfdb1ddc3b56

Closes #7698.

This class is only used on the PartialRenderer.

The iteration object is available as the local variable
"template_name_iteration" when rendering partials with collections.

It gives access to the +size+ of the collection beeing iterated over,
the current +index+ and two convinicence methods +first?+ and +last?+

"template_name_counter" variable is kept but is deprecated.

[Joel Junström + Lucas Uyezu]

Return an absolute instead of relative path from an asset url in the case of the `asset_host` proc returning nil

Just so it's clearer what's going on in the following assertion.

/cc #11993 @robin850

Also reordered some of the items to put newer ones on top (same order as
CHANGELOGs), which makes it easier to diff while we are still working on it.

Since 68574151 we are using #safe_join to
join the content when an Array is given, so we must include the dependent
module here to make sure it's available when this module is used alone.

This was making Simple Form tests to fail with current master due to the
missing dependency.

adapter, fixed from #16057 [ci skip]

(This is a manual merge of #9102)