Release of libxml2-2.7.4

* configure.in: new version
* libxml.spec.in: cleanup
* xmlregexp.c: fix a comment
* doc/apibuild.py: update
* doc/*: regenerate everything
diff --git a/doc/APIchunk22.html b/doc/APIchunk22.html
index f6501fb..7a647dd 100644
--- a/doc/APIchunk22.html
+++ b/doc/APIchunk22.html
@@ -174,6 +174,7 @@
 </dd><dt>places</dt><dd><a href="html/libxml-xmlmemory.html#xmlMemDisplayLast">xmlMemDisplayLast</a><br />
 <a href="html/libxml-xmlstring.html#xmlStrPrintf">xmlStrPrintf</a><br />
 <a href="html/libxml-xmlstring.html#xmlStrVPrintf">xmlStrVPrintf</a><br />
+</dd><dt>platforms</dt><dd><a href="html/libxml-threads.html#xmlGetThreadId">xmlGetThreadId</a><br />
 </dd><dt>plug</dt><dd><a href="html/libxml-xpath.html#xmlXPathFuncLookupFunc">xmlXPathFuncLookupFunc</a><br />
 <a href="html/libxml-xpath.html#xmlXPathVariableLookupFunc">xmlXPathVariableLookupFunc</a><br />
 </dd><dt>plugin</dt><dd><a href="html/libxml-parser.html#xmlCleanupParser">xmlCleanupParser</a><br />
@@ -524,6 +525,8 @@
 <a href="html/libxml-nanohttp.html#xmlNanoHTTPInit">xmlNanoHTTPInit</a><br />
 <a href="html/libxml-nanohttp.html#xmlNanoHTTPScanProxy">xmlNanoHTTPScanProxy</a><br />
 </dd><dt>prune</dt><dd><a href="html/libxml-tree.html#xmlReplaceNode">xmlReplaceNode</a><br />
+</dd><dt>pthread_t</dt><dd><a href="html/libxml-threads.html#xmlGetThreadId">xmlGetThreadId</a><br />
+</dd><dt>pthreads</dt><dd><a href="html/libxml-threads.html#xmlGetThreadId">xmlGetThreadId</a><br />
 </dd><dt>publicID</dt><dd><a href="html/libxml-parserInternals.html#xmlParseExternalID">xmlParseExternalID</a><br />
 </dd><dt>pull</dt><dd><a href="html/libxml-xmlIO.html#xmlParserInputBufferGrow">xmlParserInputBufferGrow</a><br />
 </dd><dt>pure</dt><dd><a href="html/libxml-parserInternals.html#xmlParseCDSect">xmlParseCDSect</a><br />