* Two different beacon animations. One color for push beacon,
   different color for pull beacon.
 * All nodes are colored differently. Whole node colorization was
   very confusing, so only a little sector of the node is colored.
 * PacketAnimation. Visualized packet movements. Packets are
   represented as little colored triagles.
 * All packets are colored according to their ultimate source node.
 * Nodes are jumping around a few pixels during beacon sending.
   Just for some restless fun.
 * Replaced etx_data with etx_table.
 * Add handling of "event send_ctp_packet".
 * Reordered rendering to remove some visual bugs. links_to_parents are
   rendered after dynamic links.