fixed ID deallocation problem based on patch from Steve Shepard fixes bug

* valid.c: fixed ID deallocation problem based on patch from
  Steve Shepard fixes bug #160893
* xmlmemory.c: improving comment.
* testapi.c: new test for xmlDictExists() is generated.
Daniel
diff --git a/doc/APIconstructors.html b/doc/APIconstructors.html
index fbe9e0c..64e8383 100644
--- a/doc/APIconstructors.html
+++ b/doc/APIconstructors.html
@@ -18,6 +18,7 @@
 <a href="html/libxml-tree.html#xmlBufferContent">xmlBufferContent</a><br />
 <a href="html/libxml-catalog.html#xmlCatalogGetPublic">xmlCatalogGetPublic</a><br />
 <a href="html/libxml-catalog.html#xmlCatalogGetSystem">xmlCatalogGetSystem</a><br />
+<a href="html/libxml-dict.html#xmlDictExists">xmlDictExists</a><br />
 <a href="html/libxml-dict.html#xmlDictLookup">xmlDictLookup</a><br />
 <a href="html/libxml-dict.html#xmlDictQLookup">xmlDictQLookup</a><br />
 <a href="html/libxml-entities.html#xmlEncodeEntities">xmlEncodeEntities</a><br />
@@ -206,6 +207,7 @@
 <a href="html/libxml-uri.html#xmlSaveUri">xmlSaveUri</a><br />
 <a href="html/libxml-parserInternals.html#xmlScanName">xmlScanName</a><br />
 <a href="html/libxml-xmlschemastypes.html#xmlSchemaCollapseString">xmlSchemaCollapseString</a><br />
+<a href="html/libxml-xmlschemastypes.html#xmlSchemaWhiteSpaceReplace">xmlSchemaWhiteSpaceReplace</a><br />
 <a href="html/libxml-parserInternals.html#xmlSplitQName">xmlSplitQName</a><br />
 <a href="html/libxml-tree.html#xmlSplitQName2">xmlSplitQName2</a><br />
 <a href="html/libxml-xmlstring.html#xmlStrcat">xmlStrcat</a><br />