integrate XmlParser and CType from haxe dev branch

new XmlParser parses the "this" nodes correctly, which fixes the crash as
described in #4. In fact, with the new CType, it no longer seems
necessary to keep our own custom CType/XmlParser, and we should just use
the one provided in std.
Merge pull request #5 from desktop/master

integrate XmlParser and CType from haxe dev branch