sorting modules, and added few more
new options: no-display, verbose-exec
much more powerfull exec engine

Now --exec recognize placeholders: {path}, {dirname}, {basename}
work always on absolute paths
deduplicate code
COnfig - allow for pass arguments in constructor
split code into named blocks (aka functions)
rename: ff_execute_prepare -> execute_prepare
editorial in error message
EAFP instead of LBYL
another rename: execute_prepare -> prepare_execute
order of declarations
simpler form of reading attributes values in Config's constructor
fix: understand argument to --exec option
process_item: rename config arg -> cfg