Added support for subtypes

[wesleytodd]

So this is much bigger than I imagined. There were quite a few things that changed because I moved the functionality for name parsing and construction more into multicast-dns-service-types, which this PR required to run (https://github.com/wesleytodd/multicast-dns-service-types/tree/v2.0.0).

Also, while all of the tests pass, I had to change some of the values in them. They where all pretty much what looked like internal use only variables. Let me know if I am mistaken.

I haven't yet tested it with my little project, I will update this when I have, but I figured I would post it to get feedback first. I can also probably test out your ipp project to for compatibility (hopefully this wont break anything), but might not be able to for a few days.

Let me know what you think!

[wesleytodd]

Probably should have been sure I was up-to-date before doing this. Will fix the conflicts and update.

[wesleytodd]

well i thought that might work on travis, but i guess not. If you clone it down though it should pass :)

[jspiro]

Hope to see this integrated someday :)

[wesleytodd]

@jspiro I obviously took a hiatus on this project....paying the bills and all that :)

But I think it is just pending work over here: mafintosh/multicast-dns-service-types#6

If you are interested in picking up where that left off it seems reasonable that this could get finished up. I unfortunately do not see me finishing this any time soon, sorry.