MSVC 2013 compatibility: fix memory corruption.

The quality of this compiler just reached a new low. Getting memory
corruption just because I didn't include the header which isn't needed
by any other compiler?!  What?!

src/Magnum/Implementation/FramebufferState.h

@@ -34,6 +34,12 @@
 #include "Magnum/RenderbufferFormat.h"
 #endif
 
+/* We did't get memory corruption like in e.g. TextureState here, but include
+   the header just to be sure */
+#ifndef CORRADE_MSVC2013_COMPATIBILITY
+#include "Magnum/Renderbuffer.h"
+#endif
+
 namespace Magnum { namespace Implementation {
 
 struct FramebufferState {

src/Magnum/Implementation/ShaderProgramState.h

@@ -31,6 +31,12 @@
 #include "Magnum/Magnum.h"
 #include "Magnum/OpenGL.h"
 
+/* Otherwise we get a pretty nice memory corruption without any warning or
+   error whatsoever (!) */
+#ifdef CORRADE_MSVC2013_COMPATIBILITY
+#include "Magnum/AbstractShaderProgram.h"
+#endif
+
 namespace Magnum { namespace Implementation {
 
 struct ShaderProgramState {

src/Magnum/Implementation/TextureState.h

@@ -39,6 +39,16 @@
 #include "Magnum/TextureFormat.h"
 #endif
 
+/* Otherwise we get a pretty nice memory corruption only with a warning about
+   architecture-dependent alignment of `setBufferImplementation` variable */
+#ifdef CORRADE_MSVC2013_COMPATIBILITY
+#ifndef MAGNUM_TARGET_GLES
+#include "Magnum/BufferTexture.h"
+#else
+#include "Magnum/AbstractTexture.h"
+#endif
+#endif
+
 namespace Magnum { namespace Implementation {
 
 struct TextureState {