Fix support calculation for gateway and remove fractional ships

[yarukishi]

The support calculation for Andromeda ships in the Gateway system incorrectly provided too much support in cases when the lowest-priority ship receiving support was a Frigate, Cruiser, or Dreadnought.

For example, suppose that the Gateway System has 32.5 support and the following ships activated: 31 Bolognium Ship > 6 Dreadnought > 5 Cruiser Ship > 2 Frigate Ship

In this situation, we expect 31 Bolognium Ships (31 support), 0.3 Dreadnoughts (1.5 support), 0 Cruiser Ships, and 0 Frigate Ships to operate.

Actually, the game operates 31 Bolognium Ships (correct), 1.5 Dreadnoughts (too many), 0 Cruiser Ships, and 2 Frigate Ships. This is a total of 31 + 7.5 + 4 = 42.5 Gateway support. It prints that only 24.5 / 32.50 support is in use.

Fixing this issue causes some ugly rounding problems with fractional ships, especially in relationship to Cruiser Ships (3 support) that are being moved around. I chose to remove fractional ship support as part of the patch.

If we want to keep fractional ships, then fixing all of the rounding issues is probably feasible.