Weapon test mode

Since it's been requested a lot, I added a weapon test mode to allow you to try out your new weapons. In this mode enemies cannot harm you and will display the damage they've taken during the last second. There's also a DPS indicator in thee middle of the screen. So that you could you armour penetration, destroying enemy bullets, etc. there are three types of enemies: normal, armoured and shooting.

When you're done testing the weapons, just move into the blue portal, and it will take you back to the inventory.

Also rebalanced minelayers.