Increased shell world's jobs.

Fixed some incorrect jobs provided by shell world's zones.

Fixed a bug where building shell world won't correctly change inner layer's planet class and capital building.
Fixed a bug where energy/minerals/food support provides too many jobs.
Fixed a bug where food support zone provides farmer jobs.

Fleet will automatically bombard the correct layer of the shell world.

Shell world requires master builders ap rather than galactic wonders ap.
Shell world will reset its incorrect capital.
Fixed some localisation errors.

Trade zone support urban building_set.
Fallen empire's ship technologies now have prerequisites.

Fixed a bug where shell worlds would sometimes incorrectly transform into other planet classes.
Fixed a bug in extragalactic exploration events where providing food to the contact generation spaceship in the M106 galaxy consumed energy instead of food.

Added some small events.
Fallen empire's shell world would not be spawned on modded planet classes.

Updated some building_sets.

Pop growth provided by advanced clone vats will square down when there are no jobs available.
Fixed some localisation errors.