Bug 397837

I'm new with docker but took the opportunity of compiling the binding generator ant it's templates according to your blog post, to finally use docker. I encountered two problems. I fixed both for me, but I'm not sure if it is the proper way.

First thing is that the mounted directories and the `WORKDIR /home/neon` in the container belonged to root. This is why neon was unable to compile since cargo could not access it's lock files. Instead of making neon a sudoer or something, I decided to modify the Dockerfile to set the permissions of the Working-directory recursively:

```
...
# extras
...
RUN useradd neon

WORKDIR /home/neon

RUN chown --recursive neon:neon ../neon

USER neon

CMD ["/bin/bash", "-l"]
```

As I said I have no Idea whether this is good practice. The second problem I encountered is that the environment variable XDG_CURRENT_DESKTOP was not set inside the script. I could not find out why, so I fixed it dirty by setting it in the script to ubuntu:GNOME (which is the content of the variable on my system).

After those two fixes, I was able to compile everything properly using the container. Note that I might have used the script different than intended:

1. I started the script with sudo, since this is the way I currently use docker (I read that it's also possible to add my user to the docker group). I didn't try that because `sudo echo $XDG_CURRENT_DESKTOP` was set up properly.

2. I use fish as my default/login shell, not bash. The variable is correctly set in /usr/bin/env bash, though. So I'm not sure if this could have been a problem. But still, it's an "unusual" anomaly that may have influence on how things work out for me.