Add depth and stencil tests. This is currently only implemented for the
OpenGL API. HelloDepthStencil is a test using the depth and stencil
buffers to do reflections. Currently clearing / stencil clearing is not
working properly.
For shared library to work on Windows to work, we need to add
declspec(export) and declspec(import) annotations to the symbols to
export. This fixes the problem by making all libraries static on
Windows, but we'll need to revisit and do proper symbol exports.
* First API design (many features missing, including input attachments)
* Metal implementation (no OpenGL yet)
* Render-to-texture demo (a little broken until we have depth buffers)
* Update examples to use render passes