Solve import order problem when POULibrary imports ConfigTreeNode because of UserAddressedException. Now UserAddressedException is declared in POULibrary.py, as a quick and dirty fix, but some independant module should be created for beremiz exceptions in general.
<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>