initial implementation of APY buildpack

yet to make it work fully.
add virtualenv support files; fix virtualenv/pip to work
env vars are added to ~/.profile.d

also use cached APY to save buildpack test cycle.
pip use mirrors
set PATH to absolute path of venv bin directory
no need to install APY
install globally, thanks to docker
working buildpack for the wsgi-helloworld app
app dir is symlinked from /app during runtime
remove unneded files
make --user install work, finally!
remove debug
include userbase bin/ in PATH
make pip output unbuffered

also cd to app dir before running pip
pypm support

specify pypm dependencies in requirements.pypm

also: cleanup pip output like heroku does.
fill in README for newcomers
remove incorrect license
add a license with AS copyright

imported from https://github.com/ActiveState/stackato-activemq-service/blob/master/LICENSE.md