avoid passing a char[] as snprintf first argument. implemented

* encoding.c parserInternals.c: avoid passing a char[] as snprintf
  first argument.
* threads.c include/libxml/threads.h: implemented xmlIsThreadsEnabled()
  based on Andrew W. Nosenko idea.
* doc/* elfgcchack.h: regenerated the API
Daniel
diff --git a/doc/APIchunk19.html b/doc/APIchunk19.html
index ade6618..5e4b9d0 100644
--- a/doc/APIchunk19.html
+++ b/doc/APIchunk19.html
@@ -307,6 +307,7 @@
 </dd><dt>multiple</dt><dd><a href="html/libxml-parserInternals.html#xmlCurrentChar">xmlCurrentChar</a><br />
 <a href="html/libxml-parserInternals.html#xmlStringCurrentChar">xmlStringCurrentChar</a><br />
 </dd><dt>multiply</dt><dd><a href="html/libxml-xpathInternals.html#xmlXPathMultValues">xmlXPathMultValues</a><br />
+</dd><dt>multithread</dt><dd><a href="html/libxml-threads.html#xmlIsThreadsEnabled">xmlIsThreadsEnabled</a><br />
 </dd><dt>multithreaded</dt><dd><a href="html/libxml-parserInternals.html#htmlInitAutoClose">htmlInitAutoClose</a><br />
 <a href="html/libxml-parser.html#xmlInitParser">xmlInitParser</a><br />
 </dd><dt>mutex</dt><dd><a href="html/libxml-dict.html#xmlDictCleanup">xmlDictCleanup</a><br />