Switch to using «The Lean Mean C++ Option Parser»

Switch to using «The Lean Mean C++ Option Parser»

Options now requires two dash before long option name.
Some option names were slightly changed, you can see all of them with "lugaru -h"
See http://optionparser.sourceforge.net/index.html for info on the parser used
Fixes #14

We may want to add a --debug option to avoid having to edit the
config.txt file for this?