Without this fix, in Internet Explorer the plist parser would only receive an empty XML document for the main Info.plist (and any other such loaded documents) if the server did not provide the content type "text/xml".
This fix parses the XML correctly even if there is no such content type.
Fixes#2051.
Previously, Cappuccino only called OBJJ_PROGRESS_CALLBACK when an executable or image sprite file was finished loading. Only a slow connection, this would result in long periods with no visible progress.
Now OBJJ_PROGRESS_CALLBACK is called continuously during download via the XHR progress event. All supported browsers except IE 9 support this event.
1. Split out flatten specific code to get file size back down.
2. Fix for non-native string URL not working with the URLCache (typeof x !=== "string")
3. Fix for slight IE performance regression.
Reviewed by me.