Added resolve_entities=False to parser init args
Code cleanup and as_dict() consistency.
* Cleaned up unneeded lines of code by better utilizing list
  comprehensions.
* Made ProfileValidationResults, SchematronValidationResults, and
  BestPracticeValidationResults as_dict() methods return a `errors`
  key which points to a list of dictionaries. Previously the value
  for `errors` was either a list or a dictionary.
Merged remote v2.0.0 branch