Faster "trust" family commands.

Accomplished by NOT searching offline players except for /untrust.
Now UUID-migrating players with $ and _ names.

Players with names starting with these special characters will now be
migrated.
Memory footprint: Claims Lookup

Eliminated unwanted chunk loads from claim lookups and boot process.
Also a slight perf improvement for claim lookup.
Memory Footprint: UUID Conversion

Saving RAM by clearing data after it's no longer needed by UUID
conversion code.
Performance: Faster player name lookup.

Especially beneficial to /trustlist and error messages (like trying to
do something in a land claim without permission).
UUID Migration Perf Tweak

Another minor tweak to save time.
Version to 8.2.3