special functional block rendering

![image](https://cloud.githubusercontent.com/assets/1767466/4741893/aecbc5ba-5a1a-11e4-86cf-98e851d3a304.png)

Bunch of code to try to make functional blocks prettier. When reviewing, focus on ways I might have broken non-calc things. I'm also going to spend some time looking at non-calc blocks to see if I can see any issues.


I thought we were going for "rounded rectangles" to approximate "circles" of evaluation