Trogdir change

The Trogdir sync code has been rewritten to hopefully simplify it and fix some of the bugs.

There are no known problems with this branch but additional testing may be required before it can be used in production.

The "Update from Trogdir" functionality has been removed. I'm hopefuly that the new code will be dependable enough that it won't be needed.

Also added an additional worker for each change for better concurrency.

WCMS-352