World Editor Limits, What is PTR?

Level 7
Sep 11, 2013
Guys I've been trying to make complicated maps with GUI triggers, I've accomplished everything I wanted in this map except removing UI interface, I tried doing the letterbox mode with user control enabled which looks definitely awesome but it removes me from using my unit. I can still move the unit since I am using arrow key movement and with the ESC key but I lack at least 2 more abilities and I can't find any other KEY that can be used in GUI. What is this PTR? I have always used the normal world editor from 1.24 to 1.26, never updated ever since, hehehe. How to update to this 1.31?