Use return() from main() rather than exit(0)... allows SDL to close

gracefully on some platforms.

src/syncdraw/options.c

@@ -393,6 +393,5 @@ exitprg(void)
 		clrscr();
 		gotoxy(1, 1);
 		printf("Thanx 4 using this syncdraw\n");
-		exit(0);
 	}
 }

src/syncdraw/syncdraw.c

@@ -1152,6 +1152,7 @@ main(int argnum, char *args[])
 			break;
 		case 0x2d00:	/* ALT+X - Exit */
 			exitprg();
+			return(0);
 			break;
 		case 0x1e00:	/* ALT+A - Color */
 			Attribute = SelectColor();