fix SNAFU with processor box bindings

Bindings were not loaded until after ProcessorBoxen were created,
meaning they had no effect (the ProcessorBoxen set their ardour
bindings to null).

Also handle leave-means-deselect at ProcessorBox level rather than
MixerStrip level, to include MonitorSection PB

gtk2_ardour/ardour_ui_dependents.cc

@@ -86,9 +86,6 @@ ARDOUR_UI::we_have_dependents ()
 	 */
 	mixer->monitor_section().use_others_actions ();
 
-	/* Create "static" actions that apply to all ProcessorBoxes
-	 */
-	ProcessorBox::register_actions ();
 	StepEntry::setup_actions_and_bindings ();
 	ClipEditorBox::init ();
 

gtk2_ardour/mixer_strip.cc

@@ -454,10 +454,6 @@ MixerStrip::mixer_strip_enter_event (GdkEventCrossing* /*ev*/)
 {
 	_entered_mixer_strip = this;
 
-	//although we are triggering on the "enter", to the user it will appear that it is happenin on the "leave"
-	//because the mixerstrip control is a parent that encompasses the strip
-	deselect_all_processors();
-
 	return false;
 }
 

gtk2_ardour/processor_box.cc

@@ -1941,6 +1941,10 @@ ProcessorBox::ProcessorBox (ARDOUR::Session* sess, boost::function<PluginSelecto
 	, processor_display (drop_targets())
 	, _redisplay_pending (false)
 {
+	if (!processor_box_actions) {
+		register_actions ();
+	}
+
 	set_session (sess);
 
 	/* ProcessorBox actions and bindings created statically by call to
@@ -2550,6 +2554,8 @@ ProcessorBox::leave_notify (GdkEventCrossing* ev)
 		gtk_window_set_focus (win->gobj(), 0);
 	}
 
+	processor_display.select_none ();
+
 	return false;
 }