Better gitar.sh

Added automated testing so that I can try to keep code quality consistent.
This also helps with debugging.

Added a new compression option: lzma.

I changed how the compression is numbered from 1-5 instead of 0-4.  This
better fits the convention of compression options for the cli utilities.
Now sets user information

I found that in some versions of sudo that the $HOME, $HISTFILE,
and $MAIL options are set for the ssh user rather than the root
user.  This leaves some undesired results in bash history and
other stuff.