beremiz

ToolChain: add IEC library include paths to CFLAGS when building C code from extensions.

This allows generated C code to include beremiz.h, and other IEC types definitions.
<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>