Reworking application launch process.  Removed old launch script 
and launcher class.  New ones are temporarily hard-coded to specific 
inputs.
Created basic dialog for getting the working directory.  Can be expanded
later into the full 'wizard'.
Added utility function for getting files in a directory with the specified 
suffix.
Running launch script now brings up the working directory selection.
Only the first .reals.astrom file found in that directory is processed.