scheduler
Delay accepts an optional second argument specifying the time unit.
scheduler doc strings.
Moved scheduler to source dir. oops.
Scheduler now has the right namespace. oops.
Removed coordinate version of the build and unbuild functions for buildings.
Ensured that functions can be scheduled from within a transaction, but that start, stop, pause and resume can't be called from within a transaction.
building predicates public.
vehicle spawn/unspawn code
function to create a circular path to/from a cell.
fixed the build.
Merge branch 'dev' into world-state