Fix mysql problems

Using `ubuntu:14.04` as a base made mysql fail to start (unable to obtain write rights) for me. Solved with basing from `phusion/baseimage:0.9.10` (see [details](http://phusion.github.io/baseimage-docker/)). 
Aside from that, needed to additionally run `supervisord` before populating the database, since it didn't automatically start with the container for some reason.
Also bower doesn't install packages under root, hence adding `--allow-root' option for this case.
The rest are minor changes.