- extract MaterialHelper and move all of its members to aiMaterial in /include.

- pull in IOhannes' patch to set the gcc default visibility for all symbols to NO and to mark ASSIMP_API with __attribute__ ((visibility("default"))).
- drop unneeded ASSIMP_API from most internal classes in /code, we just need to keep some exports on Windows to keep AssimpView alive.

git-svn-id: https://assimp.svn.sourceforge.net/svnroot/assimp/trunk@1066 67173fc5-114c-0410-ac8e-9d2fd5bffc1f

code/JoinVerticesProcess.h

@@ -46,8 +46,6 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "BaseProcess.h"
 #include "../include/aiTypes.h"
 
-struct aiMesh;
-
 namespace Assimp
 {
 
@@ -61,7 +59,7 @@ class JoinVerticesTest;
  * erases all but one of the copies. This usually reduces the number of vertices
  * in a mesh by a serious amount and is the standard form to render a mesh.
  */
-class ASSIMP_API JoinVerticesProcess : public BaseProcess
+class ASSIMP_API_WINONLY JoinVerticesProcess : public BaseProcess
 {
 public: