Fixes #361

Allow _getStringWinRT to fallback to the "strings" global when resources cannot be resolved.

This allows users to include WinJS in their package and get the default English strings by including base.strings.js and ui.strings.js.
Statically load stylesheets in ListView tests #393

Dynamically loading CSS files is an asynchronous process and our
heuristics for detecting when CSS files are done loading don't appear to
be working consistently on Saucelabs.

Make our tests more robust by statically loading CSS files instead.

Also, added a missing dispose check.
"Namespace" rules in ListView.less #393

Prefix every rule in ListView.less with a special class so that its rules
are only in effect for the tests that need the rules.
Refactor Pages to break up dependencies.

Fixes #228
Created a WinRT independent SearchSuggestionManager to use for WinJS on web.
Added tests for SearchBox-on-the-Web changes.
Disabled WebOnly tests, see #413. Fixed SearchBoxBasicTests that started failing due to the presence of a SSM shim.
Fixed JSHint errors caused by the SearchBox changes earlier.
Create build target for public modules.
Fix #376

Add animationTimeAdjustment to WWA-only code so that "Fast animations" doesn't cause Tooltip tests to fail in WWAUnitTestsApp.
added styles to center div in ie10 and safari
created test to make sure that FlipView content is centered in screen when item is smaller than FlipView
added horizontal and vertical versions of test
removed old test for checking if layout was centered
moved inactive test to bottom of the file
formatting changes
added flexbox mixins
hardcoded flipView sizes
removed unnecessary Math.ceil
changed pixelToInt calculation
Update AppBar Ellipsis invoke behavior.
closes #403
closes #404
closes #408
Fix #410

This change does a few things:
* All controls now explicitly depend on their base styling. Previously they did so implicitly due to LESS variables.
* Remove special knowledge in requirejs modular build due to the aforementioned implicit dependency.
* Remove dependency on mkpath since we have the more powerful node-fs-extras.
* Rewrite require-style to use node's "path" module for proper directory manipulation.