Pause option added. So you can easily toggle whether pings are going out
without having to fully kill pinger.
Fixed a bug where toggling the autostart option would cumulatively add
new event handlers, eventually making the program unresponsive after
several toggles.
Used argparse to enable command line arguments for
user supplied options. Defaults values have been
kept, so behavior with no arguments is the same.
Should be easier than modifying the source each
time this way.
Also added a gitignore file that is the standard
github python gitignore, plus *~ to handle
deleted files.
