Rewrite VisualEditorMessagesModule:
* Replace copy-paste dump of user-css module with stuff for
VisualEditor (class commend and module::$origin).
* Remove duplication between getMessages and getScript.
* Actually implement getModifiedTime so that the comment in
getMessages() about cache invalidation is actually true
Fixes bug 42670: ext.visualEditor.specialMessages cache broken
ve.init:
* Implement addParsedMessages and getParsedMessage so that we
don't mix up plain messages with raw html messages (minoredit
was previously overloaded in mw.msg storage with a parsed html
message and retrieved though ve.msg, which is documented as
retuning plain text, not raw html). This is now separated into
a different method.
* Improved documentation of the other msg methods to emphasise
their differences
* Removed redundant code in attachSaveDialog() that was
(partially) already done in setupSaveDialog() and moved the
remaining bits into it as well. Checked all callers of these and
they are both only called from ViewPageTarget.prototype.onLoad
* Also implement them in the standalone platform implementation,
with the html escaper based on mw.html.escape
* Update init.platform.getMessage to use undefined instead of
discouraged 'if-in' statement.
* Add test suite.
demos/test:
* Re-run makeStaticLoader.php on test to add ve.init.Platform.test
* Re-run makeStaticLoader.php on demos and update i18n caller
to use ve.init.platform.addParsedMessages (also moved out of the
auto-generated block for easier updating)
Change-Id: I7f26b47e9467e850c08b9c217c4f1098590de109