SVGHMI: added a widgets description object, accessed by id. Added frequency to widgets, as separate template to allow future customization. Excluded non svg elements (i.e inkscape Sets) with HMI: labels from widgets.
<xsd:attribute name="Compiler" type="xsd:string" use="optional" default="gcc"/>
<xsd:attribute name="CFLAGS" type="xsd:string" use="optional" default=""/>
<xsd:attribute name="Linker" type="xsd:string" use="optional" default="gcc"/>
<xsd:attribute name="LDFLAGS" type="xsd:string" use="optional" default=""/>