Minor fixes. In stand alone show the frame as soon as possible.

Especially when running Pcbnew to open a complex board the frame is shown faster.
Add also a busy cursor when loading files and building the data.

common/single_top.cpp

@@ -391,6 +391,14 @@ bool PGM_SINGLE_TOP::OnPgmInit()
 
     App().SetTopWindow( frame );      // wxApp gets a face.
 
+    // Allocate a slice of time to show the frame and update wxWidgets widgets
+    // (especially setting valid sizes) after creating frame and before calling
+    // OpenProjectFiles() that can update/use some widgets.
+    // The 2 calls to wxSafeYield are needed on wxGTK for best results.
+    wxSafeYield();
+    frame->Show();
+    wxSafeYield();
+
     // Individual frames may provide additional option/switch processing, but for compatibility,
     // any positional arguments are treated as a list of files to pass to OpenProjectFiles
     frame->ParseArgs( parser );
@@ -448,7 +456,5 @@ bool PGM_SINGLE_TOP::OnPgmInit()
         }
     }
 
-    frame->Show();
-
     return true;
 }

common/widgets/infobar.cpp

@@ -157,7 +157,7 @@ void WX_INFOBAR::Dismiss()
 void WX_INFOBAR::onSize( wxSizeEvent& aEvent )
 {
     int barWidth = GetSize().GetWidth();
-    int parentWidth = m_parent->GetSize().GetWidth();
+    int parentWidth = m_parent->GetClientSize().GetWidth();
 
     if( barWidth != parentWidth )
         SetSize( parentWidth, GetSize().GetHeight() );

eeschema/files-io.cpp

@@ -277,6 +277,10 @@ bool SCH_EDIT_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
             return false;
     }
 
+    // Loading a complex project and build data can be time
+    // consumming, so display a busy cursor
+    wxBusyCursor dummy;
+
     // unload current project file before loading new
     {
         SetScreen( nullptr );

pcbnew/files.cpp

@@ -575,6 +575,10 @@ bool PCB_EDIT_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
             return false;
     }
 
+    // Loading a complex project and build data can be time
+    // consumming, so display a busy cursor
+    wxBusyCursor dummy;
+
     // Unlink the old project if needed
     GetBoard()->ClearProject();