Allow unit tests to include or exclude test sets.

Allow unit tests to include or exclude test sets.

This modifies the command line to take test
matches of the form:

   --match [or -m] [~][^]match[$] [~][^]match[$] ...

   ~ causes a matching test to always be skipped

   ^ requires the start of the test to match

   $ requires the end of the test to match

   ^ and $ requires an exact match

If a test does not match any list entry,
it is skipped unless some list entry starts with ~
Review URL: https://codereview.chromium.org/14650009

git-svn-id: http://skia.googlecode.com/svn/trunk@8955 2bbb7eff-a529-9590-31e7-b0007b416f81