Would it be possible to include extensions as subspecs? #36
Description
From what I gather by reading #25, the recommended practice is to copy-paste source code instead of using a package manager if you want any of the extensions.
Perhaps the extensions could be supplied through subspecs in CocoaPods? It is how PromiseKit handles extensions https://github.com/mxcl/PromiseKit#extensions.
Carthage does not support subspecs, but you can emulate the behavior by having a separate repository for the optional dependencies. You can still have keep them in one repository by using git submodules.