fix discovery dialog sorting, remove services from the discovery dialog when they go offline
<xsd:attribute name="Compiler" type="xsd:string" use="optional" default="gcc"/>
<xsd:attribute name="CFLAGS" type="xsd:string" use="required"/>
<xsd:attribute name="Linker" type="xsd:string" use="optional" default="g++"/>
<xsd:attribute name="LDFLAGS" type="xsd:string" use="required"/>