BIER in non-MPLS netowrks

as decsribed in section 2.2
  ihttps://tools.ietf.org/html/draft-ietf-bier-mpls-encapsulation-10
with BIFT encoding from:
  https://tools.ietf.org/html/draft-wijnandsxu-bier-non-mpls-bift-encoding-00

changes:
1 - introduce the new BIFT lookup table. BIER tables that have an associated
    MPLS label are added to the MPLS-FIB. Those that don't are added to the
    BIER table
2 - BIER routes that have no associated output MPLS label will add a BIFT label.
3 - The BIER FMask has a path-list as a member to resolve via any possible path.

Change-Id: I1fd4d9dbd074f0e855c16e9329b81460ebe1efce
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/src/vnet/dpo/load_balance.h b/src/vnet/dpo/load_balance.h
index b901c5b..d37f07d 100644
--- a/src/vnet/dpo/load_balance.h
+++ b/src/vnet/dpo/load_balance.h
@@ -182,6 +182,7 @@
 extern const dpo_id_t *load_balance_get_bucket(index_t lbi,
 					       u32 bucket);
 extern int load_balance_is_drop(const dpo_id_t *dpo);
+extern u16 load_balance_n_buckets(index_t lbi);
 
 extern f64 load_balance_get_multipath_tolerance(void);