patch from Sean Treadway, adding Python bindings for extension element and

* python/generator.py python/libxslt-python-api.xml python/libxslt.c
  python/libxslt_wrap.h python/libxsltclass.txt: patch from
  Sean Treadway, adding Python bindings for extension element and
  some bindings cleanups.
* python/tests/Makefile.am python/tests/extelem.py: also add an
  example/test.
Daniel

python/libxsltclass.txt

@@ -19,13 +19,10 @@ registerAllExtras()
 # functions from module python
 cleanup()
 registerErrorHandler()
+registerExtModuleElement()
 registerExtModuleFunction()
 registerExtensionClass()
 
-# functions from module transform
-setXIncludeDefault()
-xincludeDefault()
-
 # functions from module xslt
 cleanupGlobals()
 
@@ -98,6 +95,7 @@ Class transformCtxt()
     shutdownCtxtExts()
 
     # functions from module extra
+    debug()
     registerExtras()
 
     # functions from module imports
@@ -118,11 +116,6 @@ Class transformCtxt()
     evalAttrValueTemplate()
     evalTemplateString()
 
-    # functions from module transform
-    applyStripSpaces()
-    freeTransformContext()
-    registerAllElement()
-
     # functions from module variables
     evalGlobalVariables()
     evalOneUserParam()
@@ -196,9 +189,6 @@ Class stylesheet()
     applyStylesheet()
     saveResultToString()
 
-    # functions from module transform
-    newTransformContext()
-
     # functions from module variables
     parseGlobalParam()
     parseGlobalVariable()