Readme update

Made some temporary changes to README.TXT. Planning to finish updating this in future commit
perfexp comments

Added comments to the perfexp script. Also included developer notes in comments for future development.
ExperimentDriver comments

Added comments to  ExperimentDriver.py. Added a few developer notes for future development.
DataManagerDriver comments

Added comments to DataManagerDriver.py
AnalysisDriver comments

Added comments to AnalysisDriver.py
ModelDriver comment

Added comments to ModelDriver.py