OS X support

[goodboy]

In an effort to avoid alienating our friends with a taste for shiny, juicy, paper thin apples.

[goodboy]

Just waiting for some feedback from someone having successfully used this branch and then we'll merge it.

OTH if we decide to lock in py3 we can use selectors and avoid being stuck on a subpar loop ;)

[vodik]

Linking #34 - but I don't think this patch will work for Windows - select there only works on sockets.

[goodboy]

@vodik as per #47 and the CI results here seems like on py3 we're royally ded. I'm hoping moving to selectors will resolve this but we need #42 and deprecation of py2 first I'm thinking.

[goodboy]

Probably deprecated by #87 if the lurkerz approve 🤔