Bug fix: Dynamic inactive dim & client window changes

- Make inactive_dim opacity change according to window opacity by
  default, so it looks better when fading. --inactive-dim-fixed restores
  the old behavior.

- Make client window default to the window itself. Add w->wmwin to
  represent whether the window looks like a WM window instead. A side
  effect is, the window type of WM windows are changed from unknown to
  normal, making it necessary to use --mark-wmwin-active to avoid
  considering them unfocused.

- Add check of PointerRoot to recheck_focus() to avoid BadWindow errors
  when the root window is focused.

- Add a few macros to simplify debugging code.

- Add DEBUG_FRAME.

compton.sample.conf

@@ -20,6 +20,8 @@ inactive-opacity = 0.8;
 frame-opacity = 0.7;
 inactive-opacity-override = false;
 alpha-step = 0.06;
+# inactive-dim = 0.2;
+# inactive-dim-fixed = true;
 
 # Fading
 fading = true;