Merge branch 'master' into v0.6.0

# Conflicts:
#	src/ifcconvert/IfcConvert.cpp
#	src/ifcgeom/IfcGeomRenderStyles.cpp
#	src/ifcgeom/IfcGeomWires.cpp
#	src/ifcparse/IfcLogger.cpp
#	src/ifcparse/IfcLogger.h
#	src/ifcparse/IfcParse.cpp
#	src/ifcparse/IfcUtil.cpp
#	src/serializers/ColladaSerializer.cpp
#	src/serializers/schema_dependent/XmlSerializer.cpp

src/serializers/ColladaSerializer.cpp

@@ -34,6 +34,8 @@
 #include <string>
 #include <cmath>
 
+#include "../ifcparse/utils.h"
+
 static std::string& collada_id(std::string& s)
 {
     IfcUtil::sanitate_material_name(s);