Use a local 'rpath' module

nstead of adding to rpython.rlib.rpath these functions which are
not tested, not used by PyPy, and more importantly which don't work
correctly on Windows.
Merge branch 'master' of github.com:hippyvm/hippyvm

Conflicts:
	hippy/bytecode_cache.py
Fix
fix translation
Merge branch 'master' into spl-iterators
Remove is_iterator and is_array_access params from def_class()

The only PHPic way of setting the corresponding attributes is to
implement Iterator and ArrayAccess, respectively
Create interfaces IteratorAggregate and Traversable
Implement IteratorAggregate protocol