add extended option to Test

The command line option
--extended runs extended tests
--verbose reports number of tests run (if recorded)

Added simple help as well.
Review URL: https://codereview.chromium.org/14063005

git-svn-id: http://skia.googlecode.com/svn/trunk@8595 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed