beremiz

Copy description when DnD variables from Globals in resources and configuration variable panels to POUs. Also prevent making exception in case some other DropSource wouldn't provide description.
<xsd:element name="Xenomai">
<xsd:complexType>
%(toolchain_gcc)s
<xsd:attribute name="XenoConfig" type="xsd:string" use="optional" default="xeno-config"/>
</xsd:complexType>
</xsd:element>