Blockly status

@BrettASwift @AmbientOSX This PR has execution tracing for the forward, left, and right blocks: highlighting in the window and display in the lower right corner of the HUD. 

This is to get something in for today, things I will continue:
- Draw blocks in hud from svg references, instead of static images
- While block inclusion

Uses virtual-world-framework/vwf#273
I managed to get stuck in this loop one time. I haven't been able to reproduce it since. I'm assuming this was executing when `clearBlocklyStatus` was called and `blockStack` was cleared. Not sure why it got stuck in the loop, though. `.alpha` was undefined when it broke. Just keep an eye out for that.