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
Fix rotate on rectangular overalys

Use size after rotate when positioning the overlay.

Also removed check on this.scales - was there a reason these were not
handled when rotating? If so we can add a option here maybe.
Revert "Fix rotate on rectangular overalys"

This reverts commit a70d082be3e9c3b961a217a712aca762f42ba653.
Merge pull request #218 from gwills/master

IE 10 not reading DZI file correctly