Basic idea for outputting proper datatypes (mock interface)

[lierdakil]

Here's a pretty barebones implementation of what I had in mind in #823, more or less.

Admittedly, didn't think too much about structure, but long story short I wanted to have at least a theoretical ability to have multiple output formats, hence OutputFormat datatype.

*OutputConfig should allow us to move things like --detail from actual library implementation to output format implementation (since, you know, library functions shouldn't have to format output, I would assume in most cases we'd like to dump all information we can to consumer) -- for now only NoOutputConfig is there.

Let me know if you'll think of improving this somehow. I won't be able to work on this much in the next ten days or so.