* Previous contents of base/ are now in base/all.

* create_node_COMMON() takes an extra argument (inserted as $3) that
  specifies the node type.  All of the create_node_* functions pass
  "$type" for this argument.

* setup_base() now has an optional argument, which is only passed by
  create_node_COMMON.  Rather than simply copying and substituting
  templates for the entire $BASE_TEMPLATES/ subdirectory it now does
  this for $BASE_TEMPLATES/all and then $BASE_TEMPLATES/$type.
  Therefore, the contents of the type-specific directory override the
  contents of "all" directory.

* releases/SoFS.common uses the "all" version of SoFS-postinstall.sh
  when setting POSTINSTALL_TEMPLATE.  This variable also now respects
  $BASE_TEMPLATES instead of hard-coding the base/ subdirectory.

Signed-off-by: Martin Schwenke <martin@meltin.net>

Both scripts now use nsd_server_common.bash to re-exec on the first
node defined in $NSD_SERVERS if that variable is set (to the list of
sofs_storage nodes by 50sofs.defconf).  They also also include the NSD
servers in the file that is passed to mmcrnsd and mmcrfs.
setup_gpfs.sh includes any NSD servers in the list of nodes for the
GPFS cluster, using them as the primary and secondary GPFS servers.
setup_gpfs.sh just sources mknsd.sh to avoid duplication of logic.

Signed-off-by: Martin Schwenke <martin@meltin.net>