Add multiple permissions to a single export

Before, each subsequent set of permissions would overwrite any previous permissions. For instance:

/media/storage *(ro,sync,no_subtree_check) 192.168.1.101(rw,sync,no_subtree_check)

would effectively be displayed as:

/media/storage 192.168.1.101(rw,sync,no_subtree_check)

This has been repaired.