BUG:Quick supplies from fighters

[john]

Since fighters get full supplies whenever they are launched and can be grouped into a fleet, a carrier that is running short on supplies can launch it's fighters into space and fleet with them. After 1 turn the supplies are shared by the fleet and when
the fighters are recaptured the carrier's supply storage is full again.

Fixing this will probably require re-doing the whole fighter supplies rules. E.g. have fighters get their supplies from the carrier, rather then from thin vacuum, but then probably one should add to fighter bays a supply capacity on top of their cargo capacity.