Fix rebaselining for Qt and Apple ports

Fix rebaselining for Qt and Apple ports
https://bugs.webkit.org/show_bug.cgi?id=90204

Reviewed by Dirk Pranke.

-Apporpriately put wk2 results in the -wk2 directories.
-Since Qt and Apple-Win don't have bots that correspond to the
platform/qt and platform/win directories, we need to fudge it
and always put the results in those directories for those ports.

* Scripts/webkitpy/layout_tests/port/builders.py:
(rebaseline_override_dir):
* Scripts/webkitpy/layout_tests/port/factory.py:
(_builder_options):
Identify webkit2 builders by the WK2 in the builder name.
* Scripts/webkitpy/tool/commands/rebaseline.py:
(RebaselineTest._baseline_directory):
* Scripts/webkitpy/tool/commands/rebaseline_unittest.py:
(TestRebaseline.test_baseline_directory):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@121577 268f45cc-cd09-0410-ab3c-d52691b4dbfc