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.

Old import code used in performance/memory comparison against libxmljs. Libxmljs is not in the dependencies, but was moved to devDependencies.