Python synthetic children:

 - you can now define a Python class as a synthetic children producer for a type
   the class must adhere to this "interface":
        def __init__(self, valobj, dict):
     	def get_child_at_index(self, index):
     	def get_child_index(self, name):
   then using type synth add -l className typeName
   (e.g. type synth add -l fooSynthProvider foo)
   (This is still WIP with lots to be added)
   A small test case is available also as reference

llvm-svn: 135865