The great directory split of 2013

Move all MW-specific files into the ve-mw directory, in preparation
for moving them out into a separate repo.

All MW-specific files were moved into a parallel directory structure
in modules/ve-mw . Files with both generic and MW-specific things were
split up. Files in ve/init/mw/ were moved to ve-mw/init/ rather than
ve-mw/init/mw ; they're still named ve.init.mw.* but we should change
that. Some of the test files for core classes had MW-specific test cases,
so those were split up and the test runner was duplicated; we should
refactor our tests to use data providers so we can add cases more easily.

Split files:
* ve.ce.Node.css
* ve.ce.ContentBranchNode.test.js (MWEntityNode)
* ve.ce.Document.test.js (some core test cases genericized)
* ve.dm.InternalList.test.js (uses mwReference test document)
* ve.dm.SurfaceFragment.test.js, ve.ui.FormatAction.test.js
** Made core tests use heading instead of mwHeading
** Updated core tests because normal headings don't break out of lists
** Moved test runners into ve.test.utils.js
* ve.ui.Icons-*.css
* ve.ui.Dialog.css (MW parts into ve.ui.MWDialog.css)
* ve.ui.Tool.css
* ve.ui.Widget.css (move ve-ui-rtl and ve-ui-ltr to ve.ui.css)

ve.dm.Converter.test.js: Moved runner functions into ve.test.utils.js

ve.dm.example.js:
* Refactored createExampleDocument so mwExample can use it
* Removed wgExtensionAssetsPath detection, moved into mw-preload.js
* Genericized withMeta example document (original version copied to mwExample)
* Moved references example document to mwExample

ve.dm.mwExample.js:
* Move withMeta and references example documents from ve.dm.example.js
* Add createExampleDocument function

ve-mw/test/index.php: Runner for MW-specific tests only

ve-mw/test/mw-preload.js: Sets VE_TESTDIR for Special:JavaScriptTest only

ve.ui.Window.js:
* Remove magic path interpolation in addLocalStyleSheets()
* Pass full(er) paths to addLocalStyleSheets(), here and in subclasses

ve.ui.MWDialog.js: Subclass of Dialog that adds MW versions of stylesheets

ve.ui.MW*Dialog.js:
* Subclass MWDialog rather than Dialog
* Load both core and MW versions of stylesheets that have both

ve.ui.PagedDialog.js: Converted to a mixin rather than an abstract base class
* Don't inherit ve.ui.Dialog
* Rather than overriding initialize(), provide initializePages() which the
  host class is supposed to call from its initialize()
* Rename onOutlineSelect to onPageOutlineSelect

ve.ui.MWMetaDialog.js, ve.ui.MWTransclusionDialog.js:
* Use PagedDialog as a mixin rather than a base class, inherit MWDialog

bullet-icon.png: Unused, deleted

Stuff we should do later:
* Refactor tests to use data providers
* Write utility function for SVG compat check
* Separate omnibus CSS files such as ve.ui.Widget.css
* Separate omnibus RL modules
* Use icon classes in ViewPageTarget

Change-Id: I1b28f8ba7f2d2513e5c634927a854686fb9dd5a5