Lots of stuff to do, for example:

Find_SSNs: fix the option processing so that the options can be given
in any order.

Find_SSNs: check for the presence of the auxilary programs at startup, and 
configure file handling appropriately.

Resview: Show output from GPG and Shred in a text box rather than the
terminal window.

Resview: Provide a file close menu item that clears the DOM and the tree.

Find_SSNs: Read an existing Find_SSNs.xml file for files to skip.

Find_SSNs: show context for text files inside a zip file.

Find_SSNs: handle docx files better - there is a Python library for this.

Resview: Allow changing the encryption key before saving a file.

Grand Plan: integrate Resview and Find_SSNs.

