Space-autobattle calculation balancing

```
The current autobattle calculation ignores limited rocket supply and performs
very different from an actual fight between two AI controlled units (e.g., turn
on AI assist with CTRL+J for your own empire and attack the AI).

The problems include:

- Limited rocket count: currently, rocket DPS is added as infinite amount fired
after cooldown
- ECM / Anti-ECM should be considered
- Station and planetary gun DPS/Defense always accounted, might be out of range.

Some resolution remarks:

- Full background simulation, i.e., a very fast version of a manual battle.
This may take some seconds, fleets should become uncontrolled during the fight.
- Do a limited simulation with turns tied to rocket launches. If a side runs
out of rockets, their dps should reflect that going onward. ECM's effect might
be computed as rocket DPS times hit probability.
```

Original issue reported on code.google.com by `akarn...@gmail.com` on 28 May 2012 at 2:07