Reorganize ecm_prep.py

[aspeake]

Fixes #438

Improve encapsulation of ecm_prep.py by breaking out code into other modules. Only the main() function in ecm_prep.py exists outside of a class now. Below is a summary of changes.

• New scout/utils.py module
  • with new class JsonIO containing json file handling methods previously in ecm_prep.Utils
  • with class MyEncoder that was previously stored in ecm_prep.py
  • with new class PrintFormat containing output format methods previously stored in ecm_prep.py (eg, verboseprint())
    • share the method PrintFormat.verboseprint in ecm_prep.py and in run.py
• New scout/ecm_prep_vars.py module
  • with class UsefulVars previously in ecm_prep.py
  • with class UsefulInputFiles previously in ecm_prep.py
  • with class EPlusMapDicts previously in ecm_prep.py
• New class ECMUtils class in ecm_prep.py to store static methods
• New class ECMPrep class in ecm_prep.py to store static methods for altering Measure and MeasurePackage instances
  • contains prepare_measures(), prepare_packages(), and split_clean_data()
• Remove unused EPlusGlobals class and associated tests
• Move breakout_mseg() to an instance method of the Measure class

To-do in a future PR

• Break up ecm_prep.main(), limiting this function to just managing the ecm_prep workflow
• New subpackage scout/ecm_prep/ which contains:
  • ecm_prep_vars.py
  • ecm_prep_args.py
  • ecm_prep_utils.py - NEW module containing ecm_prep.Utils
  • ecm_prep_measure.py - NEW module containing class Measure
  • ecm_prep_package.py - NEW module containing class Package
  • ecm_prep.py - the entry point for preparing ECMs, contains main(), prepare_measures, prepare_packages and other workflow-related functions
• Since ecm_prep.py is a little more buried, it would be nice to add an entry point scout ecm_prep that calls scout/ecm_prep/ecm_prep.py`

[aspeake]

Variable fmt conflicted with the imported class fmt

[aspeake]

This class is similar to ECMPrep, but ECMPrep is meant to store methods that update Measure and MeasurePackage instances. It might make sense to merge the two since they both contain common static methods used throughout the module.