Holster fixes and callback name update

Added a check to ensure holstering isn't done while interacting with an
item.

Updated callbacks to reflect SIF nightly changes.
Moved rcon commands to main script

Removed public whitelist functions.

Moved contents of "rcon.pwn" filterscript to "Core/Admin/Rcon.pwn".
utils update

Added a function from Emmet_ that will improve defence door movement.

Fixed a bad water-zone coordinate.
Removed some scriptfiles

Removed readmes and settings.json from scriptfile folders. These folders
(and settings) are automatically generated by the server anyway. (Plus
the readme files caused errors when various loaders tried to read them
as data files)