v2.0.1 Paratrooper changes

Changes to paratrooper assault team behaviour

When parablocking the battle will last 5 minutes if it only contains paratroopers.
The battle will end at 2 minutes 30 seconds when it says "battle is starting".
When paratrooper gets retreated but has no friendly city to retreat it will retreat on the line it landed.
This means that a retreating paratrooper can also start a new battle if it retreats to an enemy city.