Integrating aiProcess_OptimizeGraph and aiProcess_OptimizeMeshes back into the Assimp core. They're stable enough now.

Moving private members of Assimp::Importer to a pimpl, hopefully solving strange crashes with vc9 debug builds.
Updating assimp_cmd to reflect these changes.

git-svn-id: https://assimp.svn.sourceforge.net/svnroot/assimp/trunk@403 67173fc5-114c-0410-ac8e-9d2fd5bffc1f

code/JoinVerticesProcess.cpp

@@ -44,8 +44,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "AssimpPCH.h"
+#ifndef ASSIMP_BUILD_NO_JOINVERTICES_PROCESS
 
-// internal headers
 #include "JoinVerticesProcess.h"
 #include "ProcessHelper.h"
 
@@ -412,3 +412,5 @@ int JoinVerticesProcess::ProcessMesh( aiMesh* pMesh, unsigned int meshIndex)
 	}
 	return pMesh->mNumVertices;
 }
+
+#endif // !! ASSIMP_BUILD_NO_JOINVERTICES_PROCESS