Issue #2035 Calling cv::namedWindow crashes on Android fixed.

Window-related functions is guarded from calls from application code.
Old implementations with "no-gui" exception are stell compiled and linked to OpenCV library for binary compatibility.

modules/highgui/include/opencv2/highgui/highgui.hpp

@@ -54,6 +54,7 @@ struct CvVideoWriter;
 namespace cv
 {
 
+#if defined(ANDROID) && defined(HAVE_ANDROID_UI)
 enum { 
     // Flags for namedWindow
     WINDOW_NORMAL   = CV_WINDOW_NORMAL,   // the user can resize the window (no constraint) / also use to switch a fullscreen window to a normal size
@@ -155,6 +156,8 @@ CV_EXPORTS int createButton( const string& bar_name, ButtonCallback on_change,
                              void* userdata=NULL, int type=CV_PUSH_BUTTON,
                              bool initial_button_state=0);
 
+#endif
+
 //-------------------------
 
 enum