Fixed bug where attributes like ^|1 string| caused a null pointer
exception
csoar r13826: Set chunking through desirability preferences to be off by default.  (will be off for release, will be changing logic soon, and there are some reports of unanticipated changed agent behavior.)
http://code.google.com/p/soar/source/detail?r=13826
documented changes outside of semantic_memory.h/cpp