Merge pull request #1090 from w3c/jgraham/worker_navigation

Make worker navigation tests more reliable.
Tagging all instructions to human testers.
Add new test type wdspec to manifest generator

This patch adds a new test type, wdspec, short for WebDriver
specification tests to the manifest generator.

It also makes a number of improvements to tools/scripts/manifest.py.
Move webdriver client to tools/webdriver

The patch also ensures current WebDriver spec test behaviour doesn't
break.
Merge pull request #1089 from w3c/jgraham/http_content_length

Add a test for respecting the HTTP content length header.
Merge pull request #1092 from phoglund/master

Tagging all instructions to human testers.
Remove backup file.
Merge pull request #325 from martap/submission/martap

app-URI spec compliance tests
Correct the spelling of the CanvasRenderingContext2D interface in workers/semantics/interface-objects/001.html.
Merge pull request #1098 from Ms2ger/2d

Correct the spelling of the CanvasRenderingContext2D interface.
[cc] Make some ITS-in-HTML tests conformant.
[cc] Updated message.json file.
Update tests for adding manual suffix to the test file
Try to reduce the maximum stack size when running SVG sizing tests
Merge pull request #1101 from w3c/jgraham/svg_stack_size

Try to reduce the maximum stack size when running SVG sizing tests
[cc] Updated messages.json with more @sizes errors.
[cc] Add more invalid @sizes files to message.json
Merge branch 'submissions/kyohei8-ShadowRoot-olderShadowRoot' of https://github.com/kyohei8/web-platform-tests into kyohei8-submissions/kyohei8-ShadowRoot-olderShadowRoot

Conflicts:
	shadow-dom/elements-and-dom-objects/shadowroot-object/shadowroot-attributes/test-014.html
Merge branch 'kyohei8-submissions/kyohei8-ShadowRoot-olderShadowRoot'

Manually merge pull request #882 from kyohei8:submissions/kyohei8-ShadowRoot-olderShadowRoot

Comments from @hayatoito is also applied (better variable name, not
reusing the same variable for different purpose).
Partially merge pull request #598's change 1/5:

Original:
https://github.com/KenjiBaheux/web-platform-tests/commit/523b1ca44741e6fd1cf28778edbfca355d4703d1

The comment is obsolete, now 'styleSheets' property is implemented
at least on Chromium.