Patch 1.1

Hi everyone. I recieved some additional feedback since uploading final version, so here is hotfix for listed issues:

1. Messed with physics for a bit, it should be much more stable and pleasant now
2. Added rotation keeping for combined drinks
3. Added fullscreen/window mode toggle
4. Added exit confirmation
5. Refactored project for some functions (optimization)
6. Minor visual tweaks and typos corrections