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/APIfunctions.html b/doc/APIfunctions.html
index 95366f8..0e78437 100644
--- a/doc/APIfunctions.html
+++ b/doc/APIfunctions.html
@@ -211,6 +211,7 @@
 <a href="html/libxml-tree.html#xmlCreateIntSubset">xmlCreateIntSubset</a><br />
 <a href="html/libxml-parser.html#xmlCtxtReadDoc">xmlCtxtReadDoc</a><br />
 <a href="html/libxml-debugXML.html#xmlDebugDumpString">xmlDebugDumpString</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#xmlDictOwns">xmlDictOwns</a><br />
 <a href="html/libxml-dict.html#xmlDictQLookup">xmlDictQLookup</a><br />
@@ -336,6 +337,7 @@
 <a href="html/libxml-xmlschemastypes.html#xmlSchemaValidateLengthFacet">xmlSchemaValidateLengthFacet</a><br />
 <a href="html/libxml-xmlschemastypes.html#xmlSchemaValidateListSimpleTypeFacet">xmlSchemaValidateListSimpleTypeFacet</a><br />
 <a href="html/libxml-xmlschemastypes.html#xmlSchemaValidatePredefinedType">xmlSchemaValidatePredefinedType</a><br />
+<a href="html/libxml-xmlschemastypes.html#xmlSchemaWhiteSpaceReplace">xmlSchemaWhiteSpaceReplace</a><br />
 <a href="html/libxml-tree.html#xmlSearchNs">xmlSearchNs</a><br />
 <a href="html/libxml-tree.html#xmlSearchNsByHref">xmlSearchNsByHref</a><br />
 <a href="html/libxml-tree.html#xmlSetNsProp">xmlSetNsProp</a><br />
@@ -1024,6 +1026,7 @@
 <a href="html/libxml-globals.html#xmlThrDefDeregisterNodeDefault">xmlThrDefDeregisterNodeDefault</a><br />
 </p><h2>Type xmlDict *:</h2><p><a href="html/libxml-pattern.html#xmlPatterncompile">xmlPatterncompile</a><br />
 </p><h2>Type xmlDictPtr:</h2><p><a href="html/libxml-dict.html#xmlDictCreateSub">xmlDictCreateSub</a><br />
+<a href="html/libxml-dict.html#xmlDictExists">xmlDictExists</a><br />
 <a href="html/libxml-dict.html#xmlDictFree">xmlDictFree</a><br />
 <a href="html/libxml-dict.html#xmlDictLookup">xmlDictLookup</a><br />
 <a href="html/libxml-dict.html#xmlDictOwns">xmlDictOwns</a><br />