Delay redrawals on palette changes

Build on auto-sync and only mark window dirty on palette changes and let
the event handler do the actual draw.

st.c

@@ -1927,7 +1927,7 @@ strhandle(void)
 			else if (xsetcolorname(defaultfg, p))
 				fprintf(stderr, "erresc: invalid foreground color: %s\n", p);
 			else
-				redraw();
+				tfulldirt();
 			return;
 		case 11:
 			if (narg < 2)
@@ -1940,7 +1940,7 @@ strhandle(void)
 			else if (xsetcolorname(defaultbg, p))
 				fprintf(stderr, "erresc: invalid background color: %s\n", p);
 			else
-				redraw();
+				tfulldirt();
 			return;
 		case 12:
 			if (narg < 2)
@@ -1953,7 +1953,7 @@ strhandle(void)
 			else if (xsetcolorname(defaultcs, p))
 				fprintf(stderr, "erresc: invalid cursor color: %s\n", p);
 			else
-				redraw();
+				tfulldirt();
 			return;
 		case 4: /* color set */
 			if (narg < 3)
@@ -1975,7 +1975,7 @@ strhandle(void)
 				 * TODO if defaultbg color is changed, borders
 				 * are dirty
 				 */
-				redraw();
+				tfulldirt();
 			}
 			return;
 		}