delete empty scheme directory only if some file was scheduled to delete — in the same way as ICS does (CR-IC-7370)

We must follow the rule — do nothing if nothing was requested

find functional: do not process all project scope when initial interface is private and use scope is local

set selected course after step panel created

needed to correct copying of the introduction course

FileBasedIndexImpl.scheduleIndexRebuild should be in no modality state (EA-71047 - Throwable: DumbServiceImpl.scheduleCacheUpdate)

contract cache should respect the calculation time parameter count (EA-68596 - AIOOBE: ContractChecker.checkContractClause)

test commit through the GitCheckinEnvironment, not the ChangeListManager
+ avoid a deadlock during commitChangessynchronously