Use {0} initializer for all stack allocated char arrays

Lots of places in the code were already using {0} to initialize stack char
arrays, but memset() was being used as well.  This commit removes all
unnecessary memset() calls against char arrays that are already initialized
via {0} (which sets all members to zero for such arrays).
man page updates - access.conf section now includes variable guidance
[test suite] minor formatting update to access.conf files to mimic fwknoprc vars (no colon or trailing semicolon)