Removed SlowerDraw and FasterDraw buttons in Mesh panel after discussion

with Ton on IRC. This feature was old, something of a hack and didn't really
work well with the modifier stack. To paraphrase Ton: We want to make blender
higher quality, so poorly thought out code should be removed, or replaced
with decent implementations.

source/blender/include/BIF_meshtools.h

@@ -38,9 +38,6 @@ struct EditVert;
 
 extern int join_mesh(void);
 
-extern void fasterdraw(void);
-extern void slowerdraw(void);
-
 extern void sort_faces(void);
 extern void objects_bake_render(void);