Add flags to nvidia driver template:

Option "RegistryDwords" "EnableBrightnessControl=1"
Merge branch 'master' of github.com:pcbsd/pcbsd
Add some extra checks when we import old jails -> new format

Make sure IPV4 ends up with a /24 at the end

Also check at jail startup, in case somehow user imported jail with wrong config
Fix a few typos