When a PEP 302 import hook is used that doesn't implement .is_package()
an AttributeError is raised. This looks like a bug in Flask. This change
fixes that problem in the sense that it explains, that the
AttributeError is intentional.
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
The ``silent`` keyword argument to Config.from_envvar was not being honored
if the environment variable existed but the file that it mentioned did not.
The fix was simple - pass the keyword argument on to the underlying call to
``from_pyfile``. I also noticed that the return value from ``from_pyfile``
was not being passed back so I fixed that as well.