PLAYER_NEUTRAL not valid target for LEVEL_UP commands.

[PlebSupporter]

LEVEL_UP_CREATURE([player],[creature],[criterion],[levels])
LEVEL_UP_PLAYERS_CREATURES([player],[creature],[count])

These commands are not usable with PLAYER_NEUTRAL.
Doesn't throw a log error.
If it's not intended to work then that's fine; We can just amend the script commands documentation to reflect that.