Use the list of supported by app translations instead of supported translations by wx

This will make possible to translate application into locales, that
are not explicitly supported by wx: for example, 'pl' or 'bn_BD', 'bn_IN'.

                  <xsd:element name="Win32">
                    <xsd:complexType>
                      %(toolchain_gcc)s
                    </xsd:complexType>
                  </xsd:element>