Add QUnit test for ext.wikiEditor.toolbar

This patch replaces the manually operated test module for ext.wikiEditor.toolbar
with one based on QUnit. The new test suite uncovered a bug with the removeFromToolbar
API function in jquery.wikiEditor.toolbar, which prevented the removal of select buttons
from the toolbar. This issue has also been fixed in this commit. .jshintrc was updated
to ignore the new QUnit global.

Bug: T39485
Change-Id: Icef3debcffa484a8d78628bcd9da0892b750bb40
Merge "Add QUnit test for ext.wikiEditor.toolbar"