Issue 105 -- DSM2 range check mode completed.

However, I don't like that the only place I could find to turn off range check mode when the SETUP menus is exited, was in popMenu ...

void popMenu()
{
  if (g_menuStackPtr>0) {
#ifdef DSM2
    s_rangecheck_mode = 0;
#endif
    ...
}

It was the only way I could find to trap the event of [EXIT long] being pressed 
while in the RANGE field and s_editMode==true. But this solution gets executed
for all menu exits -- not just menuProcModels. It works, but there must be a
more eloquent method?

src/menus.cpp

@@ -476,6 +476,9 @@ uint8_t m_posHorz;
 void popMenu()
 {
   if (g_menuStackPtr>0) {
+#ifdef DSM2
+    s_rangecheck_mode = 0;
+#endif
     g_menuStackPtr = g_menuStackPtr-1;
     AUDIO_KEYPAD_UP();
     m_posHorz = 0;