cme: improved message about applied changes
tidied
Exception: Added ConfigFile exceptions
BackendMgr: skip backup copy if no original file is found
cme: added -create option
BackendMgr: Improved error message when no config file is found
fix comment typo and improved traces
Instance list_changes: don't list value 0 as <undef>
All backend: add 'cme edit stuff' command in header of saved file (if possible)
test for updated header with correct 'cme edit popcon' command