Removed libxml dependency, performance improvements, variadic functions, mem fixes.

New for 0.0.16:
* 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.
* Added support for adding methods for class and id members (e.g., -sel and +sel).
* Check was added to make sure null/undefined selectors cannot be passed in (previously it seg faulted rather than kicking out an error)
* Fixed crashing issue when using const "Classes" E.g., __NSStringConstant and internal types being passed through.
* Fixed issue 11 and 31 for casting bool's (e.g., returning true/false rather than 1/0), this fixed another issue I found later where an integer being passed as a BOOL wouldn't work due to the alignment.
* Fixed issue where segmentation faults happened if the size of struct was less than 16 bytes.
* Fixed garbage collection issue if a function result was passed into another obj-c function and added further memory/gc tests.
* This passes all existing unit tests, minor changes to the API (Class.addMethod deprecated to support instance and class methods).
* Moved all wrapping operations into core to further reduce circular dependencies (almost there)
* Support for variadic functions, beginning performance tests
done. see: https://github.com/TooTallNate/NodObjC/commit/259321d73791fe954dbefb25532ee9b1150b2d6b