Tests for mix-blend-mode sections 1-4 in the test plan
Add tests for the sections 4.1.5 and 4.1.6 from the blending test plan
Merge pull request #382 from Mire/mbudaes/mix-blend-mode_tests

Tests for mix-blend-mode sections 1-4 in the test plan
Merge pull request #395 from Mire/mbudaes/mix-blend-mode_video_tests

Add tests for the sections 4.1.5 and 4.1.6 from the blending test plan: http://test.csswg.org/source/test-plans/compositing-1/test-plan.html
Sync Mozilla tests as of https://hg.mozilla.org/mozilla-central/rev/a6a38ef6d142 .
Sync Mozilla tests as of https://hg.mozilla.org/mozilla-central/rev/f49cc729e9f9 .
Link to the (newly) correct canonical spec URL.
Dummy commit to force tests to be rescanned.
Dummy commit to force tests to be rescanned (undo changes).
CDO and CDC are now allowed at top level of variable values.
And update metadata_cache.
Sync Mozilla tests as of https://hg.mozilla.org/mozilla-central/rev/1cd56379b9f5 .
Sync Mozilla tests as of https://hg.mozilla.org/mozilla-central/rev/1cd56379b9f5 , part 2 (add files, oops).
Retract css-supports-027 and -028 since they use @-moz-document.
Sync Mozilla tests as of https://hg.mozilla.org/mozilla-central/rev/ad5fff4d45c0 .
Fix rel=match loop.
Restore whitespace to the way it was before fixing rel=match loop.