NuGet v2 API (for consideration)

[Emzi0767]

Might be potentially useful to implement the v2 API, seeing as a lot of NuGet clients still rely on it (which brings up the question about the point of having a v3 API if it isn't even fully functional, or, in fact, used by most-used NuGet client implementations).

One major obstacle to this goal would be the fact that the v2 API is completely undocumented. Might be useful to use something like LiGet as reference for such purpose.

Benefits of this are currently unknown. It seems to range from none to actually working VS (and any other official) NuGet client.