Merge branch 'master' into v0.6.0

# Conflicts:
#	nix/build-all.py
#	src/ifcgeom/IfcGeomFunctions.cpp
#	src/ifcparse/IfcLogger.cpp

src/ifcgeom/IfcGeom.h

@@ -80,6 +80,23 @@ if ( it != cache.T.end() ) { e = it->second; return true; }
 #include INCLUDE_PARENT_DIR(IfcSchema)
 
 namespace IfcGeom {
+	class IFC_PARSE_API geometry_exception : public std::exception {
+	protected:
+		std::string message;
+	public:
+		geometry_exception(const std::string& m)
+			: message(m) {}
+		virtual ~geometry_exception() throw () {}
+		virtual const char* what() const throw() {
+			return message.c_str();
+		}
+	};
+
+	class IFC_PARSE_API too_many_faces_exception : public geometry_exception {
+	public:
+		too_many_faces_exception()
+			: geometry_exception("Too many faces for operation") {}
+	};
 
 class IFC_GEOM_API MAKE_TYPE_NAME(Cache) {
 public: