Some unfinished useful tools (path finding, class grouping in class mode, dot generation)

[jrudolph]

I tried it on akka-http-core and, wow, there's some entanglement going on...

I needed a few extra tools to try to see what's going on:

• in class mode, treat objects and traits as classes as well so that companions are grouped together
• simple helpers to find some sample paths Cycles.pp, useful for finding concrete cycles between two classes
• dot generation (doesn't seem particularly useful on reasonably sized code bases, takes dot ages to generate a graph and the result is hardly usable)

For now, I'm just putting them out here without any cleanup as I don't know when I'll be able to come back to it.

[jvican]

CI seems to fail, though. Errors look legit.

[SethTisue]

in class mode, treat objects and traits as classes as well so that companions are grouped together

@jrudolph fwiw, if you (or anyone else watching this repo) PRed that by itself, that sounds like a good change that would be easy to merge

[SethTisue]

the dot generation part would probably be more useful if we had source-file-level and package-level aggregation