hammer2 - Implement automatic reconnect
* Somehow the actual commit wound up in a merge
e1648a68d2a340848f1c8ec7bd695c6285927392.
* When the hammer2 service daemon starts it now scans all hammer2 mount
points and attempts to reconnect itself to each one.
This allows the sysop to kill the hammer2 service daemon, which will
remote the machine's mounts from the cluster, and then later restart
it to add the machine's mounts back into the cluster.
* Fix a pthread detachment bug. Some pthreads are not tracked and have
to detach themselves to avoid a libpthread memory leak.