add random villager chance to bandit settlement town template
default template re-organization
minor updates to default town templates
clean up how towns are validated, defer validation until final loading
stage, so that all structure templates are definitely loaded.  Solves
issues of towns in structure pack attempting to load before the rest of
the structures in the pack.
add per-town seed to rng for town-generation
add enable/disable flag for town generation in structures config file
update default structure pack
meh...add enable/disable toggle for town-gen.  silly ide not saving
prior to build...wtf