preparing 2.6.24 release, fixed Python paths at the last moment fix some

* NEWS configure.in doc//*: preparing 2.6.24 release, fixed Python
  paths at the last moment
* relaxng.c testapi.c tree.c: fix some comments
Daniel
diff --git a/configure.in b/configure.in
index 835958d..6951b3d 100644
--- a/configure.in
+++ b/configure.in
@@ -5,7 +5,7 @@
 
 LIBXML_MAJOR_VERSION=2
 LIBXML_MINOR_VERSION=6
-LIBXML_MICRO_VERSION=23
+LIBXML_MICRO_VERSION=24
 LIBXML_MICRO_VERSION_SUFFIX=
 LIBXML_VERSION=$LIBXML_MAJOR_VERSION.$LIBXML_MINOR_VERSION.$LIBXML_MICRO_VERSION$LIBXML_MICRO_VERSION_SUFFIX
 LIBXML_VERSION_INFO=`expr $LIBXML_MAJOR_VERSION + $LIBXML_MINOR_VERSION`:$LIBXML_MICRO_VERSION:$LIBXML_MINOR_VERSION
@@ -678,17 +678,17 @@
 	   -d $with_python/lib/python$PYTHON_VERSION/site-packages
 	then
 	    PYTHON_INCLUDES=$with_python/include/python$PYTHON_VERSION
-	    PYTHON_SITE_PACKAGES=$libdir/lib/python$PYTHON_VERSION/site-packages
+	    PYTHON_SITE_PACKAGES='$(libdir)/lib/python$(PYTHON_VERSION)/site-packages'
 	else
 	    if test -r $prefix/include/python$PYTHON_VERSION/Python.h
 	    then
 	        PYTHON_INCLUDES=$prefix/include/python$PYTHON_VERSION
-		PYTHON_SITE_PACKAGES=$libdir/python$PYTHON_VERSION/site-packages
+		PYTHON_SITE_PACKAGES='$(libdir)/python$(PYTHON_VERSION)/site-packages'
 	    else
 		if test -r /usr/include/python$PYTHON_VERSION/Python.h
 		then
 		    PYTHON_INCLUDES=/usr/include/python$PYTHON_VERSION
-		    PYTHON_SITE_PACKAGES=$(libdir)/python$(PYTHON_VERSION)/site-packages
+		    PYTHON_SITE_PACKAGES='$(libdir)/python$(PYTHON_VERSION)/site-packages'
 		else
 		    echo could not find python$PYTHON_VERSION/Python.h
 		fi
@@ -701,9 +701,9 @@
     fi
     if test "$with_python" != ""
     then
-        pythondir=$PYTHON_SITE_PACKAGES
+        pythondir=$(PYTHON_SITE_PACKAGES)
     else
-        pythondir=$libdir/python$PYTHON_VERSION/site-packages
+        pythondir='$(libdir)/python$(PYTHON_VERSION)/site-packages'
     fi
 else
     PYTHON=