Removed libxml dependency, performance improvements, bump 0.1.1

Libxmljs is now replaced with a bridgesupport specific xml parser.

The new parser is 36% faster and lower code footprint (maintenance).  

The new parser uses 49.1% less memory (technically leaking memory fixes).

Added a few new unit tests for performance/memory. 

This passes all existing unit tests (unmodified), no changes in the API.

This is somewhat unfortunate but I had to deprecate the Class.addMethod, the addMethod was only adding class based methods (+ someSelector: ) to classes, there wasn't a clear way to add methods as instance (- someSelector:) only.  For people inheriting NS* abstract classes such as NSURLProtocol type checks are done on the instance vs. class methods.  Let me know what you think.