cleanup optcomplete, prepare for unittests
allow for Option/OptiopnParser customisation
fix missing completer is not defined
add logger support; some fixes
add initial unittests
rework optcomplete, add unittests for the completer classes
allow easier changing of shell usage
add function to create commandline for autocompletion testing with
optcomplete
add a basic autocompletion test for generaloption using the
simple_option script