Added AI, changed physics a bit
Made AI smarter

Now it's likely to stay around the center but explores the sides too.
Merge remote-tracking branch 'origin/master' into dev

Conflicts:
	studna.gmx/objects/obj_pl.object.gmx
Camera doesn't move too low now

The losing player never crosses the upper rim.
Players warp above all bricks

So they don't warp into bricks anymore.
Players are thinner now

The sprites are only 16 pixels wide now. Collision is set to the whole
sprite so we can use `sprite_width` to estimate collision box.
An arrow shows an off-screen player

When a player is too high (above view), an arrow appears and shows her
horizontal position.
Also, turned off AI control.
Added onebutton control

Now many players can play at once. Doesn't support player disconnecting
yet.
2 players, 2 buttons each
Update GameMaker: Studio to version 1.3.1380
Remove macros GM_build_date and GM_version

The macros were generated automatically and don't mix well with source control.
Make sure you disable automatic generation of the macros
by unchecking "Automatically add build number and date constants"
in general preferences.
Add a resizeable platform object (no behavior so far)

Implemented in obj_platform.
Add icons to obj_control and obj_ctrl_hotkeys
Put `spr_pl_*` in group `pl`
room_well: Don't draw background color

Background is handled by obj_background.
Add icon to obj_background
obj_background: Remove unused code (cleanup)

The code, when enabled, draws an ellipse based on first player's position.
obj_background: Add names to Execute Code actions
Remove unused background `background0`
Add icon to obj_draw_rim