Provides simple nfs service name detection via systemd or sys-v. Defaults
are provided if no match is found. Service name is defined via method
allowing derivative guests to only need to provide an updated name.
Prior to this commit, if you set up multiple folders to export with NFS
on linux with the exact same hostpath, the template used to write
/etc/exports would end up placing the same path with the same IP in
/etc/exports and cause an error preventing the folders from being
properly mounted. This commit fixes that by first looking at which
folders are being exported and if there are any duplicates. If so,
remove the duplicates and only export 1 hostpath folder. If these
duplicate folders have differing nfs linux options, an exception must be
thrown because we cannot assume which options the user intended to
export with.