mono/MonoGame — pull request #3333 by mgarstenauer (2014-12-29 19:14:56+00:00)
Title: Add TextureCubeWriter and fix for ExternalReference

In our game engine we create and write `TextureCube` via the content pipeline.

Changes:
- `TextureCubeWriter` added. Creates same output as in XNA.
- `Texture2DWriter` changed to match `TextureCubeWriter`. (Unnecessary comment/calculation removed. Output is the same as before.)

Plus, here is a fix for external references:
When an `ExternalReference` is stored in a `Dictionary` it can't be loaded at runtime. The reason is that the dictionary values are written with the `ReflectiveWriter