Fix binary search in dingliste.cc to use unsigned arithmetic.
Rework dingliste_t.  Fix null pointer bug caused by death of trees.  Rewrite code to provide much more comprehensible internal interface, and faster code when assertions are turned off.  Revise memory management strategy to save memory in common case.  Most likely eliminate other lurking bugs by virtue of cleaner interface.
Fix missing prototype in previous commit.
Fix more mismatched prototypes.
Fix ANOTHER prototype error.