Massive commit. sorry.
 * Add animation framework.
 * Layout 10 nodes in a spiral
 * Render links between nodes (width and color depend on usage freq)
 * Render lines to parents between nodes (uses a special stipple pattern
   to indicate direction)
 * Render a progress bar above nodes. Uses data from node attrs
   ctpf_buf_capacity and ctpf_buf_used.
 * Animate radio on/off states (if too quick, render a blue fade-out
   for 0.2 s after the radio is turned off.
 * integrated nanomsg. can receive and visualize events/data
   radiopowerstate, beacon, packet_to_activemessage,
   packet_to_model_busy, ctpf_buf_size
 * and more ugly unsanitized code