more testing and coverage more cleanups rebuilt Daniel

* gentest.py testapi.c: more testing and coverage
* elfgcchack.h xmlstring.c include/libxml/xmlstring.h: more cleanups
* doc/*: rebuilt
Daniel
diff --git a/xmlstring.c b/xmlstring.c
index 15ca76c..78acbff 100644
--- a/xmlstring.c
+++ b/xmlstring.c
@@ -478,6 +478,8 @@
     int size;
     xmlChar *ret;
 
+    if (len < 0)
+        len = xmlStrlen(str2);
     if ((str2 == NULL) || (len == 0))
         return(xmlStrdup(str1));
     if (str1 == NULL)
@@ -869,7 +871,7 @@
  *
  * Returns a pointer to the UTF8 character or NULL
  */
-xmlChar *
+const xmlChar *
 xmlUTF8Strpos(const xmlChar *utf, int pos) {
     xmlChar ch;