[Diet] Fixed Toolkit + Tests (#398)

These commits fix the diet branch so that everything is building again. (And the tests that pass on master pass again.) There is a little temporary code as I mentioned on the issue (#398) to fix issues with converting arrays of SharpDX.Mathetmatics values to SharpDX.Mathematics.Interop values.

Also, since I apparently can't leave comments on my own commit:
* [BinarySerializer.Mathematics.cs:45](https://github.com/PathogenDavid/SharpDX/compare/diet?expand=1#diff-6f3da2f91ad5497db9ce7be53bf2a1d3R45): Angle.Serialize used to be implemented with radiantsInt, I changed it to Radians since that is the publicly facing property. This shouldn't cause any issues because radiansInt is basically just a bit-wise cast of Radians to an int and vice-versa. However I thought I should mention it just in case.

* [BinarySerializer.Mathematics.cs:81](https://github.com/PathogenDavid/SharpDX/compare/diet?expand=1#diff-6f3da2f91ad5497db9ce7be53bf2a1d3R81): BoundingFrustum used to serialize the planes even though it had no reason to (the planes are inferred from the matrix.) Since the planes are not externally writable, I left them out. However, to maintain compatibility I left in reading/writing dummy planes.
 * A: Do we care about keeping the compatibility?
 * B: Do we want to serialize the planes anyway? If we wanted to we could if we changed the fields to internal.