sysctl(3): Update description of various kern.* variables. Also add xrefs for confstr(3) (as sysconf(3) but for strings) and kvm(3) (which is a more convenient way to access some of the variables).
sysctl(3): Update description of various kern.* variables.
Also add xrefs for confstr(3) (as sysconf(3) but for strings) and kvm(3)
(which is a more convenient way to access some of the variables).

PR:		116480
MFC after:	1 week

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase