beremiz

file isExecutable
fix non-working logging at first connection to PLC after Beremiz launch

At the same time this helps to avoid exception described in 1484:d5efbb20927e.
<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>