Improve container size

[ghost]

There are a few things we can do to optimize the size of the container to optimize download speed:

• Uninstall dependencies we actually don't need immediately after installing. I tried to do that but it proved harder than expected to find things that can be uninstalled without breaking stuff, so punting until I maybe have a bit more time. The following may be helpful in the Dockerfile, after the installation step:

  COPY rm-packages /root/rm-packages
  RUN rpm -e --nodeps $(cat /root/rm-packages) && \
  rm /root/rm-packages

  Note that you need to put the packages you want to remove into a file called rm-packages. Create a dependency diagram for DAPS, maybe -- the whole gnome-vfs2 tree looks rather unnecessary, for example, as does the libsndfile1 tree.

• Just delete unwanted binaries. One large one is inkview (70 MB uncompressed), albeit I suspect that inkscape and inkview are ~90% percent identical, so this might actually compress well.

[ghost]

We're doing all of that and it helps a little... (would help more to lose the LIbreOffice dependency).