SVGHMI: preliminary implementation of a general enable bit for all widgets, using "#" at the end of widget declaration, and a "disabled" element that becomes visible instead of widget when disabled.
<xsd:attribute name="Command" type="xsd:string" use="optional" default="make -C %(buildpath)s all BEREMIZSRC=%(src)s BEREMIZCFLAGS=%(cflags)s MD5=%(md5)s USE_BEREMIZ=1 FROM_BEREMIZ=1"/>