[MEDIUM] ebtree: upgrade to version 6.0

This version adds support for prefix-based matching of memory blocks,
as well as some code-size and performance improvements on the generic
code. It provides a prefix insertion and longest match which are
compatible with the rest of the common features (walk, duplicates,
delete, ...). This is typically used for network address matching. The
longest-match code is a bit slower than the original memory block
handling code, so they have not been merged together into generic
code. Still it's possible to perform about 10 million networks lookups
per second in a set of 50000, so this should be enough for most usages.

This version also fixes some bugs in parts that were not used, so there
is no need to backport them.
diff --git a/ebtree/ebmbtree.c b/ebtree/ebmbtree.c
index a4a0354..156f0e2 100644
--- a/ebtree/ebmbtree.c
+++ b/ebtree/ebmbtree.c
@@ -1,7 +1,7 @@
 /*
- * Elastic Binary Trees - exported functinos for Multi-Byte data nodes.
- * Version 5.0
- * (C) 2002-2009 - Willy Tarreau <w@1wt.eu>
+ * Elastic Binary Trees - exported functions for Multi-Byte data nodes.
+ * Version 6.0
+ * (C) 2002-2010 - Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -41,3 +41,37 @@
 {
 	return __ebmb_insert(root, new, len);
 }
+
+/* Find the first occurence of the longest prefix matching a key <x> in the
+ * tree <root>. It's the caller's responsibility to ensure that key <x> is at
+ * least as long as the keys in the tree. If none can be found, return NULL.
+ */
+REGPRM2 struct ebmb_node *
+ebmb_lookup_longest(struct eb_root *root, const void *x)
+{
+	return __ebmb_lookup_longest(root, x);
+}
+
+/* Find the first occurence of a prefix matching a key <x> of <pfx> BITS in the
+ * tree <root>. If none can be found, return NULL.
+ */
+REGPRM3 struct ebmb_node *
+ebmb_lookup_prefix(struct eb_root *root, const void *x, unsigned int pfx)
+{
+	return __ebmb_lookup_prefix(root, x, pfx);
+}
+
+/* Insert ebmb_node <new> into a prefix subtree starting at node root <root>.
+ * Only new->key and new->pfx need be set with the key and its prefix length.
+ * Note that bits between <pfx> and <len> are theorically ignored and should be
+ * zero, as it is not certain yet that they will always be ignored everywhere
+ * (eg in bit compare functions).
+ * The ebmb_node is returned.
+ * If root->b[EB_RGHT]==1, the tree may only contain unique keys. The
+ * len is specified in bytes.
+ */
+REGPRM3 struct ebmb_node *
+ebmb_insert_prefix(struct eb_root *root, struct ebmb_node *new, unsigned int len)
+{
+	return __ebmb_insert_prefix(root, new, len);
+}