update olsr_spf_cand_tree to olsr_spf_cand_set function
update olsr_spf_cand_tree to olsr_spf_cand_set function

update olsr_spf_cand_tree function to accept both AVL tree and Binary heap as priority
queue on SPF Algorithm

diogomg/olsrd-binary-heap,diogomg/olsrd-binary-heap,diogomg/olsrd-binary-heap,diogomg/olsrd-binary-heap,diogomg/olsrd-binary-heap,diogomg/olsrd-binary-heap,diogomg/olsrd-binary-heap