Check the process associated with the currently active window

Fixes an issue where the same process would be suspended more than once
if it had multiple windows, one of them active and the others inactive,
and the window then lost focus after a power change event (AC power being
removed).

Fixes #11

src/events.c

@@ -171,7 +171,10 @@ static
 void
 iterate_windows_kill_matching ()
 {
-    for (GList *w = wnck_screen_get_windows (wnck_screen_get_default ()); w ; w = w->next) {
+    WnckScreen *screen = wnck_screen_get_default ();
+    WnckWindow *active = wnck_screen_get_active_window (screen);
+
+    for (GList *w = wnck_screen_get_windows (screen); w ; w = w->next) {
         WnckWindow *window = w->data;
         Rule *rule = main_window_get_rule (window);
 
@@ -180,7 +183,7 @@ iterate_windows_kill_matching ()
             continue;
 
         // Skip currently focused window
-        if (wnck_window_is_active (window))
+        if (active != NULL && windows_are_same_process (window, active))
             continue;
 
         // On battery, auto-suspend windows that allow it