Add existence checks on bundle processing
Merge branch 'master' of github.com:MAECProject/python-maec

Conflicts:
	maec/bundle/bundle.py
Change comparison parameter in example
Added get_all_bundles method
Added parse_xml_instance method for parsing and returning the proper MAEC binding object for an input Package or Bundle file
Added properties existence checking in process_object
Updated get_all_objects to operate on Objects embedded in Actions
Updated get_all_objects usage in Comparator class
Initial scripts/run_comparator script commit
Merged