Update 0.2.0

- fixed issued with placing towers on corners
- fixed being able to build towers inside your home
- added highlights to buttons
- added exit/retry/main buttons to endscreen
- right click cancels building mode
- enabled timer and wave gui
- portal opens
- replaced main menu background
- nerfed D4 melee tower, more accurate attack and lower range
- enabled combat text
- added the real "start wave button"
- basic camera controls added