Workaround for SmartOS MAP_32BIT w/ broken hints: -DBROKEN_MMAP_HINTS
Prefer Circonus' forked version of libnetsnmp (libnetsnmp-c)

Required if you want to build the snmp.so module.
Still allow lua snmp bindings against regular libnetsnmp if no libnetsmp-c.
if people want to build a patched libnetsnmp-c, here's the patch
don't build snmp.so if we don't have libnetsnmp-c
fix old lib name to corrected lib name
change buildling into markdown
default to sha256 digest when generating requests
Change posix logging to files to be asynchronous.

Change the asynch jlog writer to be generic and leverage it
for the posix logio implementation.  Normal "fd" logging used
for stderr is still synchronous, but all posix against files is
asynchronous.
posix_logio_reopen needs to spawn a new writer thread in async mode.

If this doesn't happen we won't write correctly across a fork.
Fixes issue #213: SSLv2_server_method not correctly detected.
If auth_method is set to auto and no auth is required, work.
Merge branch 'master' into MTEVerest
quiet compiler warnings