CON-82: Don't crap out on corrupt transaction recovery

This commit prevents the recovery of a corrupt transaction
from preventing server startup.

1. Add better logging about block syncing
2. Add better logging about when transaction recovery actually happens
3. Gracefully handle the case when we try to recover a corrupt transaction

Conflicts:
	concourse-server/src/main/java/org/cinchapi/concourse/server/storage/db/Database.java