When selecting an expression of an assignment and then selecting another

expression, the background of the first expression did not revert to its 
original color.

- gui_style.h (COLOR_CHOICE_SELECTED): made blue a bit lighter, to improve
  contrast of black foreground text
- gui_frame.c (unselect_value): build_assignment uses COLOR_EXPR_PASSIVE for
  expressions in assignments, so we also have to do the same here.



git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5763 99fdad57-331a-0410-800a-d7fa5415bdb3

obj.h

@@ -42,7 +42,7 @@ struct value {
 	struct expr *expr;
 	struct value *next;
 
-	/* back reference */
+	/* back reference, NULL if loop */
 	struct row *row;
 
 	/* for the GUI */