Merge branch 'master' into python3

diff --combined wrw/sp/cons.py
index 99656a3,ff6a1b1..3b6ec2c
--- 1/wrw/sp/cons.py
--- 2/wrw/sp/cons.py
+++ b/wrw/sp/cons.py
@@@ -4,18 -4,18 +4,18 @@@ import xml.dom.minido
  class node(object):
      pass
  
 -class text(node, unicode):
 +class text(node, str):
      def __todom__(self, doc):
          return doc.createTextNode(self)
  
 -class raw(node, unicode):
 +class raw(node, str):
      def __todom__(self, doc):
          raise Exception("Cannot convert raw code to DOM objects")
  
  class element(node):
      def __init__(self, ns, name, ctx):
          self.ns = ns
 -        self.name = unicode(name)
 +        self.name = str(name)
          self.ctx = ctx
          self.attrs = {}
          self.children = []
@@@ -23,13 -23,13 +23,13 @@@
      def __call__(self, *children, **attrs):
          for child in children:
              self.ctx.addchild(self, child)
 -        for k, v in attrs.iteritems():
 +        for k, v in attrs.items():
              self.ctx.addattr(self, k, v)
          return self
  
      def __todom__(self, doc):
          el = doc.createElementNS(self.ns, self.name)
 -        for k, v in self.attrs.iteritems():
 +        for k, v in self.attrs.items():
              el.setAttribute(k, v)
          for child in self.children:
              el.appendChild(child.__todom__(doc))
@@@ -44,9 -44,10 +44,9 @@@ class context(object)
  
      def __init__(self):
          self.nodeconv = {}
 -        self.nodeconv[str] = lambda ob: text(ob, self.charset)
 -        self.nodeconv[unicode] = text
 +        self.nodeconv[bytes] = lambda ob: text(ob, self.charset)
 +        self.nodeconv[str] = text
          self.nodeconv[int] = text
 -        self.nodeconv[long] = text
          self.nodeconv[float] = text
  
      def nodefrom(self, ob):
@@@ -59,11 -60,13 +59,13 @@@
          raise Exception("No node conversion known for %s objects" % str(type(ob)))
  
      def addchild(self, node, child):
+         if child is None:
+             return
          node.children.append(self.nodefrom(child))
  
      def addattr(self, node, k, v):
          if v is not None:
 -            node.attrs[unicode(k)] = unicode(v)
 +            node.attrs[str(k)] = str(v)
  
  class constructor(object):
      def __init__(self, ns, elcls=element, ctx=None):