Improved reliability of the packet obfuscation key update function

Follow-up to 38b8bf0

Solves some edge cases where, depending on key and packet combination,
the key may not be correctly updated and leads to a forced
disconnection.

Signed-off-by: Haru <haru@dotalux.com>
Fixed GM Commands
Fixed @nextlevel command
Added leveling quests
Merge branch 'master' of https://github.com/HerculesWS/Hercules