Various touchups & fixes

Removed unused imports
Added an alias to flatfile in /mmoupdate
Removed vestiges of /mmoupdate confirm system
Commented PURGE_TIME
Add getSkillMapFromLine for powerless purge & flatfile leaderboards
Add tryClose() for non-repetition glory
Synchronize access to the flatfile database, to avoid data loss
Add @SuppressWarnings to PlayerUpdateInventoryTask
Use getGeneratedKeys() to avoid an extra query on player creation
Change default of readId to -1
SQL: saveUser calls newUser() on id read failure
SQL: fix loadPlayerProfile behavior on not-found player names and orphaned data rows