osx: fix annoying focus behaviour (@anticat)

https://github.com/Proxmark/proxmark3/pull/689

OS X has a global menu bar and a per app dock icon. Therefore, all
GUI applications launched from a terminal will become focused - even
if they don’t show any windows. Thereby the terminal loses focus.

Since is it very annoying to re-focus the terminal after each proxmark
client launch, this change makes the client unfocusable during launch
and restores the regular behaviour when a window is created.

client/proxguiqt.cpp

@@ -27,6 +27,10 @@
 #include "proxgui.h"
 #include <QtGui>
 
+extern "C" {
+#include "util_darwin.h"
+}
+
 bool g_useOverlays = false;
 int g_absVMax = 0;
 int startMax;
@@ -53,9 +57,14 @@ void ProxGuiQT::_ShowGraphWindow(void) {
 	if(!plotapp)
 		return;
 
-	if (!plotwidget)
+	if (!plotwidget) {
+		
+#if defined(__MACH__) && defined(__APPLE__)
+		makeFocusable();
+#endif	
+	
 		plotwidget = new ProxWidget();
-
+	}
 	plotwidget->show();
 }
 
@@ -100,6 +109,12 @@ void ProxGuiQT::MainLoop()
 	//start proxmark thread after starting event loop
 	QTimer::singleShot(200, this, SLOT(_StartProxmarkThread()));
 
+#if defined(__MACH__) && defined(__APPLE__)
+	//Prevent the terminal from loosing focus during launch by making the client unfocusable
+	makeUnfocusable();
+#endif
+
+	
 	plotapp->exec();
 }