Trying to fix issue #208, no success; CleanupMergeDatabaseFilesScenarioTest fails

Old code cherry picked, should work because we decoupled
database file numbers from vectorclocks

Conflicts:
	syncany-lib/src/main/java/org/syncany/operations/cleanup/CleanupOperation.java
Fix queries to check for chunks in dbvs as well and fix numbers in test to reflect new situation