Clean up and fixes needed to run `isecdem` without errors.

- Converted all tabs to spaces.
- Enforced 80-character lines.
- Removed unnecessary shebangs and comments.
- Added tsharkpanel to package.
- Added generated Debian package to .gitignore
Refactor main application.
Added a more graceful exit, fixed error on quit.
Cleaned up imports and documented unimplemented method.
Dried up wireless device enumeration.
Abstracted TShark into its own module, except for mdnsmon0capture.py.