.NET Core compatibility

[ForNeVeR]

We aim to produce fully-fledged cross-platform solution, and we already support two common CLI implementations: Windows CLR/.NET and cross-platform Mono.

A couple of days ago .NET Core was released, and I think that we want to support it. We'll need to estimate any code and/or infrastructure changes required to add .NET Core support.

Maybe we'll want to define it as our main target platform, because, if I understand correctly, all existing Mono and CLR implementation are somehow compatible with .NET Core (i.e. it's a common denominator), and the new set of .NET Standards is a nice way to define compatibility level of our project (e.g. if we're compatible only with the latest desktop runtime versions then it's sufficient to declare netstandard1.6, and we should try to support most of the lower versions in our own runtime components to make sure programs compiled by Naggum may be run anywhere).

[ForNeVeR]

I'll research the current situation and report back here before making any big decisions.