Fixed runtime with twisted but without Wx (-x 0 -t 1), made non-Zeroconf a default option, i.e when -n not specified
<xsd:element name="Xenomai">
<xsd:complexType>
%(toolchain_gcc)s
<xsd:attribute name="XenoConfig" type="xsd:string" use="optional" default="/usr/xenomai/bin/xeno-config"/>
</xsd:complexType>
</xsd:element>