basic set of tests for shape-outside + shape-box
Tests for bidi section of CSS Writing Modes 3
Update path for sync-tests.sh.
Sanitize bugs out of reftest manifests better.
Sync Mozilla tests as of https://hg.mozilla.org/mozilla-central/rev/869971ad9fd6 .
update full-width tests.

* update tests and reference to use vertical-rl per suggestion from editor.
* use text-combine-upright: all mainly where possible
* add tcu: all + tt: full-width case as 002 (former 002 is now 003)
* small editorial changes.
Merge pull request #562 from yunxiaoxie/yunxiaoxie/css3-flexbox

Remove tests of css3-flexbox in work-in-progress
Add reference file for background-clip
removed tests 001 & 005. since shape-outside: margin-box on a plain div float has the same effect as if no shape-outside property was set, it's not testable.  margin-box tests are covered elsewhere with polygons, circles, and images.
Merge pull request #547 from rhauck/shape-box-tests

basic set of tests for shape-outside + shape-box
Merge pull request #563 from myakura/myakura/text-combine-upright-9_1_3_1

Reviewed LGTM. CSS Writing Modes: tests for `text-combine-upright` on fullwidth characters
Merge pull request #560 from r12a/r12a/css-bidi

Screening and running this, LGTM. :Tests for bidi section of CSS Writing Modes 3
merge
Merge pull request #564 from chenxix/chenxix/csswg-test/background-clip

Add reference file for background-clip
Move css3.png from resource folder to support