Starting work on global workers.
Some bugfixes.
Remove _workers attr of workspaces.
Some locks needed to be tightened.
CopyvioSource.workspace should be public.
Add a bunch of temporary debugging code.
Bugfix.
Fix dequeueing logic a bit.
Fix stopping queues in local mode.
Fix variable.
Only spawn one worker for comparisons in local mode.
Fix a blocking issue.
Handle empty queues correctly. Remove some log messages.
source.join() now blocks when in the middle of processing.
Use a deque for a FIFO instead of the python list LIFO.