Add optional "cleanup" param to editFile. [1303]

Defaults to False. If True, the Jython Shell input field will have the
following lines of code to the beginning of the input field text
(*before* the actual file contents):

    # removeAllData and removeAllLayers were added because editFile was
called with "cleanup" set to True.
    removeAllData()
    removeAllLayers()
Use expandpath within editFile. [1303]

This allows users to provide paths like "$HOME/lol.py".
Commented out most print statements. [1303]

The only print output should be limited to warning messages.