Code:
#define IDLE_WHEN_EMPTY
This will build the source so that when a zone is empty, it will go idle. If you comment it:
Code:
//#define IDLE_WHEN_EMPTY
Then even when a zone is empty, it will not idle (aka "truly static" zone -- mobs will still path, do their thing, timers, etc.). Though, there is no reason I can think of (at this time) to comment that (using //) before building the source, unless you have zones as static in your 'launcher_zones' table. But I haven't investigated it either.