Demo updates v. 0.21 - v. 0.25

I think this is the last major demo update for now. I've received a lot of useful feedback from all of you, and now I'm going to focus on developing the full game.

• Improved shooting, hitting enemies is now a little easier. - Melee attacks force enemies to back off a bit. - Slightly reduced melee damage. - Melee uses stamina. - Saving the game manually reduces your sanity slightly. - While you are under the influence of a booster, your sanity decreases by 1 unit every 10 seconds. - The restroom door no longer requires a password, but you will need to find a fuse. - Items dropped by enemies are now more visible. - Bug fixes.