Added test:all and test:all:db tasks to speed up full test runs

Speed up depends on the number of test phases (N) you have for your
app, but it is roughly a 1/N improvement. In my app, it goes from
15.51s to 5.56s.

Inspired by http://ngauthier.com/2012/02/quick-tests-with-bash.html

Reviewed by @tenderlove

Add --rc description on the command line

Use --rc=PATH instead of --rc PATH

Improved `assert_template` when matching :locals with partials

previously when a partial was placed inside a directory
(eg. '/dir/_partial'), `assert_template` did not replace
the '_' prefix when looking through rendered tempaltes,
which resulted in an error.

I modified it to replace both, the leading '_' and the last '_'
after a '/'.

When `assert_template` is used with the :locals option, and the
partial was not rendered, a method_missing error was raised.
This changes first checks, if the partial actually was rendered
and raises a descriptive error.

test for issue 8931

Put .rdoc at the end of the files named RUNNING_UNIT_TESTS

So that they are printed nicely on GitHub.

Add --no-rc description on the command line

Fix link to point to new RefineryCMS repo

I feel this is too detailed for the guide. Most of that is not public interface,
and if tomorrow something is added or removed in those chains we do not want
to come here to maintain it. Also, linking to a gist is not a good idea in a guide.

We could have a more broad description of what goes in what order, the most key and
public things.

This reverts commit 862a05ed.

Add --rc option to support the load of a custom rc file

Remove BestStandardsSupport References

Starting a line with an octothorpe makes an <h1>

so that the tester's local .railsrc file does not affect the test results

Add --no-rc option to skip the loading of railsrc file

Use \A in Regexps

Convert int, float, and bools from ENV['DATABASE_URL'] query args