(messy, despite transplant)

--HG--
rename : tests/bugs/ext_instance_type_T232.pyx => tests/run/ext_instance_type_T232.pyx

cleanup and simplification, moved some optimised builtin list methods into the transform to see how it works out

currently providing optimisations for
- getattr(o,a)
- getattr(o,a,d)
- X.append(o)
- L.append(o)
- list.append(L,x)

Split int/float division cases for efficiency, make it work even if C compiler takes floor (don't know of any that do).