Small stats changes;
A few other small things
Fix: You can now click the pause and game over buttons after scrolling
disabled upgrade-icon added, if not enough money to upgrade
coordinates changed to float
projectile and unit are now MoveableGameObjects
deleted some unused imports; added a few java-doc comments
Towers can be selled
Merge branch 'master' of https://github.com/David-GER/MOW-Game

Conflicts:
	src/de/thm/mow/game/td/model/Tower.java
Clean up
fix that projectiles which doesn’t hit anything are deleted
changed delete-icon for towers into sell-icon
Small changes
Merge branch 'master' into netzwerk

Conflicts:
	src/de/thm/mow/game/td/UiManager.java
	src/de/thm/mow/game/td/model/Tower.java
	src/de/thm/mow/game/td/screens/GameScreen.java
Merge branch 'netzwerk' of https://github.com/David-GER/MOW-Game into netzwerk