Fix ActiveSupport::Testing::Isolation on jruby

Hopefully the first of many related to #11700.

With these changes the railties tests wont 100% pass but at least they
will run and show the errors.

The first problem was the @method_name variable was never set.
This was causing ENV["ISOLATION_TEST"] to always be nil which
would cause the test output to never be written to the tempfile.

The second problem was that an invalid -t option was being passed
to minitest and minitest was erroring out.

The third problem was the run method needs to always return an
instance of the test class it is trying to isolate. We were returning
a ProxyTestResult instead.
Replaced quotation marks for term by apostrophe

in getting started guide for section 5.6

[ci skip]
Added action_view in Rails::Info
Merge pull request #11720 from arunagw/added-av-in-rails-info

Added action_view in Rails::Info
Add timeout to test_async_stream

Without timeout:
this test executed infinitely on JRuby
Passes on MRI

With Timeout:
this test gracefully fails on JRuby
Passes on MRI, tested on v2.0 & v1.9.3
Merge pull request #11716 from jetthoughts/use_backquote_for_terms_in_getting_strated

Replaced quotation marks for term by apostrophes in getting started guide [ci skip]
As we are doing debug mode on

we don't need to silenced it
Merge pull request #11722 from arunagw/removed-deprecation-silenced-from-test

As we are doing debug mode on
Merge pull request #11712 from atambo/activesupport_testing_isolation_jruby

Fix ActiveSupport::Testing::Isolation on jruby
Fix jruby warning when capture calls unlink on an open tempfile

Jruby cannot unlink a tempfile unless it is closed first.
Merge pull request #11725 from atambo/jruby_capture_unlink

Fix jruby warning when capture calls unlink on an open tempfile
Merge pull request #11721 from gaurish/join-timeout

Add timeout to test_async_stream
add a test for concat on hm:t associations
Isolate railties Generators Tests

With this change jruby should pass all of the railties tests.
Merge pull request #11726 from atambo/isolate_generator_tests

Isolate railties Generators Tests
Revert "Isolate railties Generators Tests"

This fixes railties tests in JRuby but break it in MRI
This reverts commit fea99276c7024f183bf72a16ad9f36af4bae1d42.
use flat_map
Updated the guide to say that the localisation file for validation messages is in activemodel, not activerecord
Avoid calling define_method with non-english chars in InflectorTest

When we call define_method with non-english chars like ¿por qué? it
errors out on JRuby as of 1.7.4 & would leave out the following error

invalid byte sequence in US-ASCII

To work around this issue, I have switched to define_test method call
define method with fixed string & the index of the hash. the index was
added because otherwise, ruby will raise method redefined warning.

As far as I can see there are no side-effect of this change for
other implementations. For readbility I have added a message to
asssert_equal informing for which word/phase the test has passed.

Before this Change:
JRuby:
Tests terminated suddenly with an error. no reported of Failues
or errors
MRI:
All Green.

After this Change,
JRuby:
the `ActiveSupport` TestsSuite gracefully fails with report at the end which test failed & why.
MRI:
All Green(no change)
Using URI.parser.unescape

Fixes warning

warning: URI.unescape is obsolete