- Added check to clear skill unit group that created by NPC/script before the NPC/script unloaded.
- Changed enum for NPC subtype, added prefix NPCTYPE_. See map.h::npc_subtype.
- Changed Channel_Config struct usage to -> extern struct Channel_Config channel_config.
- Added restriction for atcommand that cannot be executed when Player is in autotrade, to prevent map crash. (bugreport:9196) TODO: Check other atcommand or change this behavior.
- Added enum for atcommand restriction with prefix ATCMD_NO. See atcommand.c::e_atcmd_restict.
- Updated atcommand documentations.
- Changed dummy_sd's attributes to group_id & group_level 99, and gives all permissions (PC_PERM_ALLPERMISSION). dummy_sd is being used by 'atcommand' or 'useatcmd' script when no rid/player attached.

Signed-off-by: Cydh Ramdh <house.bad@gmail.com>