Added default GM project

GM version: v1.2.1224
Added first room: room_well
Some demo of dynamic background
Black & white gradient
Basic platforming behavior

Walks around and falls down when not standing on a solid object (wall).
Increased room speed to 60 (from 30)
Some platforming, gravity etc.
spr_pl_red: Wider bounding box
Lower gravity, higher maxvspeed, simpler behavior
Added scrolling camera (view)

Scrolls below room!
Controlled by obj_control.
Added two player multiplayer

Players are controlled by:
1: left, right
2: A, D
Refactor: objects placing in editor
Added a comment
Player warps up when too low in camera
Added a comment
Camera doesn't warp up with players
Destroy wall if it leaves the view on the top edge
Level is generated randomly
Counts and draws score for individual players
Added lines to show dangerous and safe area