Have freebsd port use pkg info if the freebsd version is >= 10000017

The port package provider for FreeBSD was not checking if the freebsd version is version 10. This causes the provider to attempt to use 'pkg_info' instead of 'pkg info'. This PR should fix this bug.
we did notice that #supports_pkgng? is duplicated in the provider and resource. Not sure if there's a good place to put it elsewhere though, which is probably why it just ended up being duplicated.