System.ValueTuple support

[Banjobeni]

I'd like to use System.ValueTuple structs/tuples. They would simplify some (lightly) algorithmic code I am writing for better displaying relevant tracks to the user. In later .NET/mono frameworks, valuetuple support is integrated. If (i have no idea, really) the game updates the a newer mono version, it will most likely include System.ValueTuple in the framework.

Meanwhile I would therefore like to add https://www.nuget.org/packages/System.ValueTuple to the solution. Do you see any problem with that?