SVGHMI: add ScreenSaver feature. Automatically jumps to a page named "ScreenSaver" after timeout defined in page arguments.
<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>