adding gidget config file to git ignore list.
adding initial configuration file handling
picking up latest changes from 'develop' and merging into feature/gidget-config.
updating branch with lastest changes from 'develop' into feature/gidget-config
adding interpolation to config file; adding some programmatically-generated defaults for config; test of using config to set env vars in subprocess.
adding documentation on ConfigParser's case conversion.
updating feature branch from current develop (Merge branch 'develop' into feature/gidget-config)
Merge pull request #14 from cancerregulome/feature/gidget-config

Feature/gidget config
Merge pull request #15 from cancerregulome/master

bringing work-in-progress gidget-config changes back to develop