Animators

# Animators!
Animator interfaces and implementations. VerticalBarPlot animator refactor.

## Explicit-only scale projectors
.project(attrName, accessor, scale) now passes the accessor value through the scale ONLY if it is EXPLICITLY provided as the 3rd argument.

## Auto-Resize
Component now has .autoResize() method for enabling auto-resize!

Animators are disabled during window resize if you use auto-resize.

One thing I'd like feedback on is how to cleanly de-register auto-resize listeners when components are removed. Otherwise they will be pinned in memory by their broadcaster listeners.
What if we just call `.transition(null)` or something? Is there a null transition in D3?