[Draft] text area position input selection

This probably isin't ready to be merged, but I think presents an interesting concept:

To allow position parameters to be tuned using a Leap Motion controller.  Functionally, the code would use regex to detect variables in the JS editor, and when the cursor is in position, allow a pinched-hand to be used to adjust the numbers in z,y,z at the same time, rather than keyboard shortcuts. 

It's done as far as detecting when the cursor is over a variable, but hasn't been leap-enabled yet.

![screenshot 2014-10-09 15 37 35](https://cloud.githubusercontent.com/assets/407497/4600181/ea2f3da2-50cf-11e4-8cbb-cfb3ddb66feb.png)

I have to put this down for a few days, but would be excited to resume work when possible.