#632: data_validator.py, update docblock
Merge pull request #633 from jeff1evesque/python_data_validator

#632: data_validator.py, update docblock
#632: data_validator.py, further adjust docblock(s)
Merge pull request #634 from jeff1evesque/python_data_validator

#632: data_validator.py, further adjust docblock(s)
Merge branch 'master' into python_svm_training
#637: svm_training.py, add 'xml_to_json' method call