Round 4 of wx3 changes

This gets FileDialog updated and working on Windows.  It also
removes removes the "wx3" build configurations and makes the default
Debug and Release builds wx3-only.

Still need to get VSTs updated.

src/effects/VST/VSTControl.h

@@ -38,8 +38,6 @@ public:
       mParent = parent;
       mLink = link;
    
-      DontCreatePeer();
-   
       if (!wxControl::Create(parent, wxID_ANY, wxDefaultPosition, wxDefaultSize, 0, wxDefaultValidator, wxEmptyString))
       {
          return false;

src/effects/VST/VSTControlMac.mm

@@ -106,6 +106,8 @@ VSTControl::~VSTControl()
 
 bool VSTControl::Create(wxWindow *parent, VSTEffectLink *link)
 {
+   DontCreatePeer();
+   
    if (!VSTControlBase::Create(parent, link))
    {
       return false;

src/effects/VST/VSTEffect.cpp

@@ -38,7 +38,10 @@
 
 #include <limits.h>
 #include <stdio.h>
+
+#if defined(__WXMAC__)
 #include <dlfcn.h>
+#endif
 
 #include <wx/app.h>
 #include <wx/defs.h>