Pause research and production

```
Research and production (R/P) is constantly drawing money. There should be an
option to temporarily pause R/P without cancelling any orders.

The quick research and quick production panels may have a play / pause button
for this. Paused R/P might show up as red blinking text. Add the "paused" info
to the tooltips of the quick buttons.

Find a place on the research+production screen where the same play / pause
button might be shown.

Make sure the switch of player cheat doesn't leave an AI player with R/P
disabled ???
```

Original issue reported on code.google.com by `akarn...@gmail.com` on 13 Aug 2012 at 12:32