Updated to v1.2

This update is minor but is also an important playability improvement.  In this update I smoothed over a control issue and made pressing backwards do nothing (from whatever direction you were going).  previously it killed you.

Background:

In previous versions (v1.1 and before) if you were moving to the right and you pushed to the left you lost a life and had to start the level over.  This was because, technically, at that point you had moved into  yourself (your head had entered a pixel which was the color of your body) and therefore you died.  To the computer it was the same as if you were coming at a part of your body perpendicularly and ran right into it.  

And technically thats true, and it is something that the player can learn not to do in time.  I noticed during play testing with other people that it happened kind of a lot, and especially happened when the situation got more tense, and at those moments it was most frustrating and least fun to have an instant death button always on hand.  It was happening a lot and was not a fun part of the game so I disabled it.  

I disabled it in a fun way like this pseudocode: 

if (previous direction was left or right) and (new direction is left or right) then go in the previous direction

Same for up and down.