This replaces the "refresh" menu option with a "force maintain" option.
Allows you to maintain the base even if it doesn't need it to either get
all your items in sync or if you are going away or similar.
Tested with:
dze_permanent plot true/false
z_singlecurrency true/false
Also fixes an undefined variable error in system_monitor that was
introduced
8f58baf3f2
* Plot / door management userlist sorting
This correctly sorts the nearby humans list in both mods, I have this
running on my 1051 server with no issues, @ebaydayz please advise if
this is not right, I've tested it pretty well and it is indeed selecting
the right person/UID
* Door/plot management fixes
As per @ebaydayz