Fix/update RPM packaging files

This updates the spec to include the info on 0.16.4-1 (I didn't commit this when I built the package, d'oh). It also makes some fixes to the sourcing of the default file that would cause needed variables not to be created if they didn't exist (or were commented out) in the default file. Finally, the sanity checks have been fixed so that the initscript doesn't simply exit silently if the path to the master/minion/syndic is unset or set to an invalid path.