Changes on target-generating and loot

- Through a logical mistake there were very few units generated at each
target. The number of enemies now doesn't depend on the players progress
anymore. The mission now might be harder in the beginning.

- It was really hard to get 4th and 5th tier weapons and ammo. Better
objects are now easier to obtain (loot changes)

- Advanced start doesn't grant as many objects anymore. Especially there
are fewer vehicles.

- Some changes for lifting in the logistics system. Whole thing needs to
be rethought.

- Changed the description and added and overview/loading picture