Thing Edit Form: a warning is now displayed when a thing doesn't have any...

Thing Edit Form: a warning is now displayed when a thing doesn't have any skill or class or game mode flags.
Game Configurations: moved "thingflagscompare" from Game to Map format blocks. "Check stuck things" check now works properly in Doom/Boom game configurations.
Map Analysis: fixed a possible crash during "Check texture alignment" check.
Map Analysis: ResultStuckThingInLine now highlights both thing and line.
Map Analysis: ResultStuckThingInThing now highlights both things and allows to delete any of them.
Internal, Map Analysis: rewritten parts of "Check stuck things" class.
Internal, Map Analysis: changed the way processed stuff is stored in "Check texture alignment" class.
Internal: changed CurrentDomainOnUnhandledException, so ExceptionDialog with proper info shows up even if adding exception to the Event Log failed.
Internal: changed format, in which thingflagscompare info is stored.