remove an assertion as a workaround

This condition is also checked in CheckSanity() and it is triggered
in case a starbase is built somewhere not over a sun system.
fix troop display in planet bottom view

Stuff was drawn overlapping with the other text due to recent
enhancements.
when upgrading buildings, keep their on/offline status

Was particularly annoying in the case of defense buildings and becomes
annoying again in the case of energy buildings ignored by manager,
such as continuum scanner in an area where there are enough
alternative sources of scanning power.
If there are several of the same type, the last instance determines
the status, but the on/off rules don't differ.