Update location of w3c shapes tests to reflect new import location

Update location of w3c shapes tests to reflect new import location
https://bugs.webkit.org/show_bug.cgi?id=118156

Reviewed by Dirk Pranke.

Partial imports should not be imported to the same place as the full
import, so this adds an option to allow importing to a different
location than the default. In doing that, I found that imports from
contributor directories didn't seem to be working correctly, so I
updated the import to be smarter about both contributor directories
and the test status directories. It should now be more likely that the
script guesses the root directory properly.

* Scripts/webkitpy/w3c/test_importer.py: Remove comment about the
    script not working with the full set of contributors, as that is
    no longer true, and I didn't see a good way to keep that behavior.
    Also update documentation to properly explain what happens when a
    contributor dir is imported.
(main): Attempt to find the proper repo dir by looking at the
    directory above the "test status" in the given path, this is still
    not exactly right, but is less error prone than just trimming.
(parse_args): Add -d option to set the import directory.
(TestImporter.__init__): Stop appending the subdirs to the
    destination_directory because it was making things more complex
    and isn't really needed.
(TestImporter.update_test_status): Remove hardcoded strings and use
    the TEST_STATUS constants instead.
* Scripts/webkitpy/w3c/test_importer_unittest.py:
(TestImporterTest.test_import_dir_with_no_tests_and_no_hg): Add
    support for new option.
(TestImporterTest.test_import_dir_with_no_tests): Ditto.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@153545 268f45cc-cd09-0410-ab3c-d52691b4dbfc