copy _compat.py from flask in here (and adapt docstring)
ported some more stuff to py 3.3

removed init_jinja_globals hack from app.py after consulting mitsuhiko
(didn't work on py 3.3 "as is")

removed with_statement future imports, not needed any more

needs more work on 2.7 as well as on 3.3
Merge pull request #736 from ThomasWaldmann/sprint-branch

some more work on py 3.3 port