replaced __clear-all-and-reset-ticks, moved set-histogram-bar-number

Replaced __clear-all-and-reset-ticks with clear-all at beg of
setup and reset-ticks at end, as suggested by comment inserted
with __clear-all-and-reset-ticks by NetLogo.

Also moved set-histogram-bar-num to almost immediately after
cropplans is done being setup.