Fix mount.active command on FreeBSD.

Uses `mount -p` on FreeBSD as neither of the `/proc/self` files
currently used to determine active mounts exist on FreeBSD systems.
Ensure mount options come before special and node.

Fixes calls to mount where an fstype is specified.
Ensure mount options in remount come before special + node.

Fixes calls to mount where an fstype is specified.
Merge pull request #5187 from geoffgarside/freebsd-mount

Fix salt.modules.mount for FreeBSD