https://bugs.freedesktop.org/show_bug.cgi?id=55890
Fixed typos, serial comma, and removed "either" as there were more
than two options. Also did an extra rename of "system-shutdown"
to "systemd-shutdown" that was forgotten in commit
8bd3b8620c
Since the binary name is now hidden away in /usr/lib/ the primary user
handle for the udev service is the unit name, hence change the man page
to be available under the unit name, and make the binary name an alias
for it.