Docker base image

[incaseoftrouble]

Given that we now (or: soon #1044 ) have a somewhat reliable way of running benchexec in docker, there might be some merit in lowering the entry barrier even more and providing a standard docker image.

I think with debian as base image this should be decent to maintain and appeal to a broad audience.

EDIT: Not sure how much can be accessed from inside a controller but it could make sense to also include, for example, the pqos_wrapper, cpu-energy-meter, etc. inside that image. This would make using these optional dependencies much easier.