sysctl -p should be called with /sbin/sysctl -p

While playing around with this module on Debian 7, I noticed that "sysctl -p" is called without the full path. 

Puppet even complains about it:
sysctl -p' is not qualified and no path was specified. Please qualify the command or specify a path.

I therefore recommend using /sbin/sysctl -p in manifests/vim init.pp.
