Added Input File widgets to Parameters Editor

The feature you requested has been implemented.

Note: I don't mean to keep doing this tug-of-war with how the import statements are formatted.  I've been getting a lot of import errors when trying to run ChipSeqGui and TheWaveGenerator, and need to fix them before I can test if my code works.

There must be some differences in the way our system environments are set up (maybe something to do with the PYTHONPATH environment variable)