Make wxFileDialog::Set/SetPath() behave consistently.

wxFileDialog::GetPath() didn't return the value set by a previous call to
SetPath() in wxMSW version. Fix this and also implement SetPath() and
SetDirectory() methods in the generic versions in the same way as
SetFilename().

Closes #3672.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62722 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/generic/filedlgg.h

@@ -61,6 +61,10 @@ public:
 
     virtual ~wxGenericFileDialog();
 
+    virtual void SetDirectory(const wxString& dir)
+        { m_filectrl->SetDirectory(dir); }
+    virtual void SetFilename(const wxString& name)
+        { m_filectrl->SetFilename(name); }
     virtual void SetMessage(const wxString& message) { SetTitle(message); }
     virtual void SetPath(const wxString& path)
         { m_filectrl->SetPath(path); }