Merged Google Summer of Code sculptmode/multires/retopo tools.

From the tracker:
https://projects.blender.org/tracker/index.php?func=detail&aid=5018&group_id=9&atid=127

source/blender/src/editview.c

@@ -90,6 +90,7 @@
 #include "BIF_toolbox.h"
 
 #include "BDR_editobject.h"	/* For headerprint */
+#include "BDR_sculptmode.h"
 #include "BDR_vpaint.h"
 #include "BDR_editface.h"
 #include "BDR_drawobject.h"
@@ -1073,6 +1074,10 @@ void set_active_base(Base *base)
 				DAG_object_flush_update(G.scene, tbase->object, OB_RECALC_DATA);
 			}
 		}
+
+		if(base->object->type==OB_MESH && G.f & G_SCULPTMODE) {
+			set_sculpt_object(base->object);
+		}
 	}
 }
 
@@ -1416,6 +1421,9 @@ void mouse_select(void)
 			
 			/* selecting a non-mesh, should end a couple of modes... */
 			if(basact->object->type!=OB_MESH) {
+				if(G.f & G_SCULPTMODE) {
+					set_sculptmode();
+				}
 				if(G.f & G_WEIGHTPAINT) {
 					set_wpaint();	/* toggle */
 				}