Drop support for Python classic classes

There were only needed to support Python < 2.2, and we now require at
least Python 2.6.

 Conflicts:
	.travis.yml
	Examples/test-suite/python/autodoc_runme.py
	Source/Modules/python.cxx

This is a cherry-pick and merge from patch in #1261

Examples/test-suite/python/overload_template_fast_runme.py

@@ -1,9 +1,5 @@
 from overload_template_fast import *
 
-
-def is_new_style_class(cls):
-    return hasattr(cls, "__class__")
-
 f = foo()
 
 a = maximum(3, 4)
@@ -145,9 +141,6 @@ if (nsoverload() != 1050):
     raise RuntimeError, ("nsoverload(const char *)")
 
 
-if is_new_style_class(A):
-    A.foo(1)
-else:
-    A_foo(1)
+A.foo(1)
 b = B()
 b.foo(1)