I f...ed up the default configuration of schemas and --relaxng option

* configure.in xmllint.c: I f...ed up the default configuration
  of schemas and --relaxng option display in xmllint, pointed by
  Morus Walter.
* xlink.c: Sean Chittenden pointed a couple of errors in the XLink
  detection module, fixes bug #105374.
Daniel
diff --git a/xlink.c b/xlink.c
index 17ec77f..d7fc602 100644
--- a/xlink.c
+++ b/xlink.c
@@ -147,9 +147,9 @@
      */
     type = xmlGetNsProp(node, BAD_CAST"type", XLINK_NAMESPACE);
     if (type != NULL) {
-	if (!xmlStrEqual(type, BAD_CAST "simple")) {
+	if (xmlStrEqual(type, BAD_CAST "simple")) {
             ret = XLINK_TYPE_SIMPLE;
-	} if (!xmlStrEqual(type, BAD_CAST "extended")) {
+	} if (xmlStrEqual(type, BAD_CAST "extended")) {
 	    role = xmlGetNsProp(node, BAD_CAST "role", XLINK_NAMESPACE);
 	    if (role != NULL) {
 		xmlNsPtr xlink;