Replace ext/ dir with more structured organization of code (client, server, iso/shared)?

[Martinsos]

The idea is to split ext/ into client/, server/ and iso/. So then we would copy client/ and iso/ to client, and server/ and iso/ to server. That actually sounds like a good solution for the problem we currently have, which is that we copy all the files everywhere and then get warnings and what not. It also makes it clearer which code is nodejs and which is just javascript.
Naming might be better though, e.g. it could be shared/ instead of iso/. Or maybe names could be js/, nodejs/ and iso/ - but that is maybe too technical.

As mentioned by @shayneczyzewski , Meteor is doing smth similar:

Yep, I do indeed remember client/ and server/ having special meaning in Meteor. I think anything else was loaded in both, and lib/ had some special load order I think. You also got Meteor.isClient and Meteor.isServer to help you do the right thing in files loaded in both contexts.

[Martinsos]

We also got feedback that ext/ is a bit of a weird name. Makes sense! We should probably name it somehow differently.