Selectmenu: Delay trigger until after the list closes

Closes gh-7197
Fixes gh-7076
Toolbar: Back button correctly appears/disappears on external toolbar

This commit makes the following modifications:
1. Rename _addBackButton() to _updateBackButton() and move the decision making
   as to whether to add or remove a back button from _setOptions() into
   _updateBackButton().

2. Call _updateBackButton() from refresh() as well. This will cause the back
   button to be updated whenever the page changes, because the "pageshow"
   handler is hooked up to refresh().

3. Modify _addHeaderButtonClasses to not recognize the back button as a left
   button.

4. Modify the preconditions for adding a button to include an alternative to
   checking the page's URL for instances where there is no page present - i.e.
   when the toolbar is external. In such cases one must add a back button if
   the active item on the history stack is not the first item.

Closes gh-7188
Fixes gh-6950
Transitions: Correct exception in unit tests

Fixes gh-7458
Flipswitch: Clean up integration tests page

Fixes gh-7443
Build: Update source location for jquery.js

Fixes gh-7479
Build: Remove changelog which was accidentally committed
Build: Added jshint in external/jshint

Fixes gh-7421
Events: Fixes the problem that touchend events were stopped

(preventing vmouseup-s) if taphold is set to prevent a following tap event

This refines the modifications made in gh-5983.

Closes gh-6719
Fixes gh-7494
Re gh-5983
Navigation: Replace start( 1000 ) with start() to fix tests
Forms: Unbind from pageshow to stop reset test calling start() twice
Tests: Fix miscellaneous path-related 404s in the tests
Controlgroup: No need to delay unit test run
Degrade Inputs: Stop checking object.length and correct number of tests
Build: Upgrade to QUnit 1.14.0
Panel: use self._off for panelclose instead of document.off

Fixes gh-7058
Closes gh-7260
Panel: Fix bad function reference in unit tests

Fixes gh-7500
Closes gh-7501