IE 10 not reading DZI file correctly

IE 10 is treating the data coming back from the JSONP request as a
string and not as XML. I have confirmed this issue is happening on
numerous IE10 machines but have not seen it on any other browser.

The change simply checks the type of the data variable and if it is a
string it parses the string as XML and updates the data object.
Use $.parseXml for parsing string as XML
Small formatting change

Needed to change spacing to pass through jshint
Button event signatures fixed for consistency

Button event signatures now "handlerMethod(eventSource, eventData)"
where eventData == { button }
changelog.txt update for button event signatures
Add coordinates conversion methods to viewport.
Pinch zoom fix

The existing code failed on iPhone Safari iOS 6.x - event.detail was
always 0 causing only zoom out behavior.
changelog update for pinch zoom fix
changelog.txt update for Button event signatures
changelog.txt update for event signature change
Merge remote-tracking branch 'origin/Touch-Bug-Fix'
Merge remote-tracking branch 'upstream/master'
changelog.txt update for TileSource event sigs
Merge branch 'master' into Button-Event-Signatures
Post-merge quick fix
Check that zoom reference point is valid before using it
Add similar refPoint validity check to zoomBy
whitespace formatting change
Rollback basic.html and create coordinates.html.
Fix unit tests.
Fix documentation.
Merge remote-tracking branch 'upstream/master'