o Document that dlsym()'s behaviour with new special handle RTLD_SELF
o Document that dlsym()'s behaviour with new special handle RTLD_SELF

o Add cross reference to dlinfo(3)
o Minor mdoc nits

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