Added ai.world8 which includes map donors.

+: removed unused functions in ai.world7 and ai.world7
+: commented out printing to terminal on click
Added file for mapdonors, dev.world16, changed ai.world8.

Reworked maps as memory rather than inventory items.
The dev.world16 namespace demonstrates the use of a map. The ai.world8
namespace is a challenge to develop user agents that can survive in a
world with ventboxes, key donors, and map donors.