Screenshot via Test Listener integration

If derived from FunctionalTest, tests will generate screen shots
in the event of before & after click, navigating to a new url, or
test exception.
clean up code a bit
rename class
create test rule for screenshot
will delete screenshot if test fails
unify test screenshot directory location
add screenshot rule to frequent failing test
try to make test more stable
rename class
rewrite test rule so that it will unregister afterwards
use junit RunListener control screenshot

- By default all tests will have screenshot and screenshots are deleted if test passes
- Add NoScreenshot annotation to disable screenshot for test class or method
annotate NoScreenshot for stable tests
Merge pull request #213 from zanata/webdriver-screenshots

Screenshot via Test Listener integration