fix filesystem names / internal utf-8 encoding problem in rebasing / caching

Signed-off-by: Lucian Muresan <lucianm@users.sourceforge.net>
'fail' messages harmonized a bit, they all print 'FATAL: ' in front of the actual message
improved usage info output also for those modules without real options
bugfix in sync & update
more robust code and debug output of exclude patterns logic when rebasing