fixed large negative numbers not getting formatted correctly
fixed function that gets key types to correctly analyze keyed .attrs()
fixed timeline text layering bug
renamed the generic "chart" drawing variable to "vars.viz"
fixed some group mouse events and rectangle sizing
added links limit public variable
fixed timeline calling .draw() too many times
implement click-to-recenter, added link limit check, and fixed multiple small bugs
added buffer for rectangle rounded corners to make sure they render as circles
fixed bug in timeline when years are spaced out in data
added link exit transition
checks for connections, if app requires it
big updates to the beta ui code