Blender Git Loki

Fix compilation on linux (with gcc4.7).

Without const, I had the following error:

/home/i7deb64/blender-2.5-svn/__work__/freestyle/source/blender/freestyle/intern/python/BPy_ViewMap.cpp: In function �??PyObject* ViewMap_scene_bbox_get(BPy_ViewMap*, void*)�??:
/home/i7deb64/blender-2.5-svn/__work__/freestyle/source/blender/freestyle/intern/python/BPy_ViewMap.cpp:120:54: error: invalid initialization of non-const reference of type �??BBox<VecMat::Vec3<double> >&�?? from an rvalue of type �??BBox<VecMat::Vec3<double> >�??
In file included from /home/i7deb64/blender-2.5-svn/__work__/freestyle/source/blender/freestyle/intern/python/BPy_ViewMap.cpp:3:0:
/home/i7deb64/blender-2.5-svn/__work__/freestyle/source/blender/freestyle/intern/python/BPy_Convert.h:81:12: error: in passing argument 1 of �??PyObject* BPy_BBox_from_BBox(BBox<VecMat::Vec3<double> >&)�??
/home/i7deb64/blender-2.5-svn/__work__/freestyle/source/blender/freestyle/intern/python/BPy_ViewMap.cpp:121:1: warning: control reaches end of non-void function [-Wreturn-type]
make[2]: *** [source/blender/freestyle/CMakeFiles/bf_freestyle.dir/intern/python/BPy_ViewMap.cpp.o] Erreur 1