WIP breaking stuff: updating docker image build process for Python 3.6

This requires a new way to pass requirements.txt files to Docker (since
they now link to each other), as well as building Python ourselves (since
even Ubuntu 16.10 doesn't have a decent Python 3.6).

This is just a WIP commit, will be fixed soon(ish).

docker/1_base/base.docker

@@ -1,16 +1,10 @@
-FROM ubuntu:16.04
+FROM ubuntu:16.10
 MAINTAINER Francesco Siddi <francesco@blender.org>
 
-RUN apt-get update && apt-get install -qyy \
+RUN apt-get update
+RUN apt-get -y dist-upgrade
+RUN apt-get install -qyy \
     -o APT::Install-Recommends=false -o APT::Install-Suggests=false \
-    python-pip libffi6 openssl ffmpeg rsyslog logrotate
+    openssl
 
-RUN mkdir -p /data/git/pillar \
-&& mkdir -p /data/storage \
-&& mkdir -p /data/config \
-&& mkdir -p /data/venv \
-&& mkdir -p /data/wheelhouse
-
-RUN pip install virtualenv
-RUN virtualenv /data/venv
-RUN . /data/venv/bin/activate && pip install -U pip && pip install wheel
+RUN mkdir -p /data/git/{pillar,config,venv,wheelhouse,python}