Object Mode: Grid: Allow more subdivision in orthographic views

2.7x was displaying 2 additional subdivision for theses views. Bumping to 3
just to say we improved it!
Hypothetically it can be increased as much as we want but float precision
can quickly become an issue.

source/blender/draw/modes/object_mode.c

@@ -502,6 +502,11 @@ static void OBJECT_engine_init(void *vedata)
 
 		}
 		else {
+			if (rv3d->view != RV3D_VIEW_USER) {
+				/* Allow 3 more subdivisions. */
+				grid_scale /= powf(v3d->gridsubdiv, 3);
+			}
+
 			float viewdist = 1.0f / max_ff(fabsf(winmat[0][0]), fabsf(winmat[1][1]));
 			grid_res = viewdist / grid_scale;