Improved algo for exclusion

show deletion progress
minor refactoring
First version after start of redesign to calculate before acting
Not yet ready for publication
No reporting
Probably several bugs
Still not really as fast as I'd like
New approach working basically, but reporting needs work
and a few things to check....
Fix broken bkfd stuff
Refactoring basically complete with new approach
Still some sillies at the very top level if source or dest are files not directories
Needs more testing and possibly better reporting
Fixed a few reporting issues
Version 2 now ready to publish.
Probably still a few issues, but in general enough better than 1
to make this worthwhile.
Based on new approach which leads to major speed up on large hierarchies with relatively few changes.