resume should be tested here, since it is set if task is set and resume is set.
Clear resume here, just in case.
RunConversion now sets some global varaibles to tell what the current task and next task are.

Makes it possible for conversion steps to be atomic.
Add checkpoint for resume into GetPhysVssHistory.
Clear resume.
FixupParentActions is now one big transaction.
Indented.
Consolidated warning message output.
Think this will allow resume to work for GitReadImage.
Added more prepared statements.
Added prepare_cached statements.
Added prepare_cached statements.
Added prepare_cached statements.
Added prepare_cached statements.
Added prepare_cached.
Added prepare_cached.
Fixed error message.
Added prepare_cached.
Add an empty commit for "git rev-parse HEAD" not to fail.
Stuff isn't discarded anymore.