Used the correct munin way by soursing "$MUNIN_LIBDIR/plugins/plugin.sh" and use clean_fieldname. For the title I removed the replacement of / by __ and on the multigraph value I added the usage of clean_fieldname to make it backwards compatible.
#969 zfs/zfs_list: Add support for dash in zfs_list
ceph, samba, zfs into "fs" apache into "webserver" lighttpd into "webserver" ..