Settings window
Added a settings window with the following new features:
- Changing background color
- Changing damage number visibility
- Changing master/sound/music volume
- Toggling anti-aliasing for gameplay
- Centering the window when in windowed mode
Damage numbers
- Changed to show all damage numbers by default
- Changed visuals to outlined text
- Large performance improvement to reduce lag spikes in high spawn waves
Multi-monitor fixes
- Fixed not launching on the main monitor
- Added saving which monitor the game was on
Other
- Window mode setting is now saved
- Delayed showing the game window on launch to reduce flickers and flashes
- Changed anti-aliasing to be off by default