some warning removal on Igor's patch seems I messed up with #106788 fix

* uri.c parser.c: some warning removal on Igor's patch
* tree.c: seems I messed up with #106788 fix
* python/libxml.c: fixed some base problems when Python provides
  the resolver.
* relaxng.c: fixed the interleave algorithm
  found 373 test schemas: 364 success 9 failures
  found 529 test instances: 525 success 4 failures
  the resulting failures are bug in the algorithm from 7.3 and
  lack of support for params
Daniel
diff --git a/parser.c b/parser.c
index db83a52..ce67e54 100644
--- a/parser.c
+++ b/parser.c
@@ -10356,7 +10356,7 @@
 	return(NULL);
     }
 
-    canonicFilename = xmlCanonicPath(filename);
+    canonicFilename = (char *) xmlCanonicPath((const xmlChar *) filename);
     if (canonicFilename == NULL) {
 	if (xmlDefaultSAXHandler.error != NULL) {
 	    xmlDefaultSAXHandler.error(NULL, "out of memory\n");