fix problem with clearing non-empty location field after changing type of config variable
introduced by cd9db17 ("clear variable location cell in variable
panel, if variable class or type changed").
Closes #26
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.