Totally revamped XMLParser, as per Tim's suggestions.
Merge branch 'master' of https://github.com/whittenjaw85/pysimiam into test

Conflicts:
	scripts/controller.py
	scripts/xmlparser.py
Pushed the template parameter to the constructor for XMLParser instead of the parse method.
Fixed merge problems
Merge remote-tracking branch 'origin/test' into test
Simplified sensor hierarchy. Made simobjects cache worlld envelope.