* Implemented BestSize cache

* Added calls to InvalidateBestSize where things affecting BestSize
  are modified.  There are probably several other places where this
  still needs to be done...

* Added wxWindowBase::GetBestFittingSize that will merge the BestSize
  into the MinSize, (if any) and return the result.

* SetBestFittingSize will now only set the MinSize to the value that
  was passed to it, without merging in the BestSize


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@28010 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/gauge.cpp

@@ -72,10 +72,13 @@ void wxGauge::DoSetGauge()
 
 wxSize wxGauge::DoGetBestSize() const
 {
+    wxSize best;
     if (HasFlag(wxGA_VERTICAL))
-        return wxSize(28, 100);
+        best = wxSize(28, 100);
     else
-        return wxSize(100, 28);
+        best = wxSize(100, 28);
+    CacheBestSize(best);
+    return best;
 }
 
 void wxGauge::SetRange( int range )