when creating a DOCTYPE use "html" lowercase by default instead of "HTML"

* HTMLparser.c: when creating a DOCTYPE use "html" lowercase
  by default instead of "HTML"
* parser.c xmlreader.c: optimization, gain a few % parsing speed by
  avoiding calls to "areBlanks" when not needed.
* include/libxml/parser.h include/libxml/tree.h: some structure
  extensions for future work on using per-document dictionaries.
Daniel
diff --git a/xmlreader.c b/xmlreader.c
index cdc4f9e..a8ec578 100644
--- a/xmlreader.c
+++ b/xmlreader.c
@@ -1125,6 +1125,7 @@
     ret->sax->endElement = xmlTextReaderEndElement;
     ret->characters = ret->sax->characters;
     ret->sax->characters = xmlTextReaderCharacters;
+    ret->sax->ignorableWhitespace = xmlTextReaderCharacters;
     ret->cdataBlock = ret->sax->cdataBlock;
     ret->sax->cdataBlock = xmlTextReaderCDataBlock;
 
@@ -1152,6 +1153,10 @@
     ret->ctxt->_private = ret;
     ret->ctxt->linenumbers = 1;
     ret->allocs = XML_TEXTREADER_CTXT;
+    /*
+     * use the parser dictionnary to allocate all elements and attributes names
+     */
+    ret->ctxt->docdict = 1;
     return(ret);
 }