explore automatic GUI testing in VS2015, cmake and travis

local works vary good in windows with VS2015

source/gui/wvl.cpp

@@ -13,6 +13,22 @@
 
 #include <nana/gui/wvl.hpp>
 #include <nana/gui/detail/bedrock.hpp>
+#include <thread>
+
+#include <iostream> 
+
+
+//#define NANA_AUTOMATIC_GUI_TESTING
+
+inline unsigned Wait(unsigned wait = 0)
+{
+#ifdef NANA_AUTOMATIC_GUI_TESTING
+	return wait;
+#else
+	return 0;
+#endif
+}
+
 namespace nana
 {
 	namespace detail
@@ -23,8 +39,33 @@ namespace nana
 		}
 	}
 
-	void exec()
+	void exec(unsigned wait, std::function<void()> f )
 	{
+		#ifdef NANA_ADD_DEF_AUTOMATIC_GUI_TESTING
+				if (!wait)
+					wait = 10;
+				if (!f)
+					f = []() {API::exit(); };
+		#endif
+
+		wait = Wait(wait);
+
+		std::cout << "Will wait " << wait << " sec...\n";
+		std::thread t([wait, &f]() 
+		              { if (wait) 
+		                   {   
+							   std::cout << "Waiting " << wait << " sec...\n";
+							   std::this_thread::sleep_for(std::chrono::seconds{ wait } ); 
+							   std::cout << "Waited !! running... \n"  ;
+		                       f(); 
+							   //API::exit();
+							   std::cout << "Runed... \n";
+		                   }
+		              });
+		
 		detail::bedrock::instance().pump_event(nullptr, false);
+
+		if (t.joinable())
+			t.join();
 	}
 }//end namespace nana