beremiz

fix twice shown error message box, when wrong non-valid IEC identifier entered

It happens when non-valid name for variable name or name of field in
structure entered. This issue is described in details here:
http://trac.wxwidgets.org/ticket/16333
Project overview
================
In order to target the widest possible range of programmable devices and keep efficient, Beremiz use C code as an intermediate language.
To be executed, C needs to be compiled. `GCC <http://gcc.gnu.org>`_ serve that purpose perfectly.
PLC program is expressed in languages defined in IEC-61131, including graphical languages. Thanks to PLCopen TC2, those graphical languages have a standardised representation, in XML.
To be continued.