Prone position

[morggin]

I would like to suggest adding an additional button function from the crouching position to go into a prone position from crouching.  From a prone position give us the option to crawl face up or face down.   This could also be used with a small bonus to sneak by slowly crawling around zombies to remain beneath there notice.  This would allow us to crawl through one-block holes.  Maybe with the new character models in Alpha 22?  This would also allow us to go prone on our beds to look like we are sleeping.

Edited March 26 by morggin (see edit history)