I thought we were trying to set up some sort of library repository were we would be able to port exisisting libraries to the 
, something like the Arduino libraries.
If that was the intention I believe it would be better if we could provide those libraries in a portable format (whenever possible), so that developers will be able to produce code without having to worry too much about the end platform. The idea might be an utopia, but for what I've seen so far most of the libraries should be able to adopt this convention quite easily.
I wasn't aware of the existence of USE_SPARK_CORE_V0? definition, in fact I was asking if that was available already in my first post, so thanks a million for pointing that out. I believe point 2 from @zachary is going to be better long term solution, but I don't feel it as urgent considering all the other stuff.
Regarding the library repository, I believe we need an official github repository (something like contrib-libraries) into which we can put all those libraries, may be with a name qualifier (compat?) to declare if the library is back-portable to Arduino or not... Just loud thinking here, I don't have enough experience on C programming to know what are the difficulties here...