logical handling in python and small fixes

src/ifcwrap/utils/type_conversion.i

@@ -123,6 +123,7 @@
 	PyObject* pythonize(const int& t)                   { return PyInt_FromLong(t);                                                                  }
 	PyObject* pythonize(const unsigned int& t)          { return PyInt_FromLong(t);                                                                  }
 	PyObject* pythonize(const bool& t)                  { return PyBool_FromLong(t);                                                                 }
+	PyObject* pythonize(const boost::logic::tribool& t) { return boost::logic::indeterminate(t) ? PyUnicode_FromString("UNKNOWN") : PyBool_FromLong((bool)t) ;}
 	PyObject* pythonize(const double& t)                { return PyFloat_FromDouble(t);                                                              }
 	PyObject* pythonize(const std::string& t)           { return PyUnicode_FromString(t.c_str());                                                    }
 	PyObject* pythonize(const IfcUtil::IfcBaseClass* t) { return SWIG_NewPointerObj(SWIG_as_voidptr(t), SWIGTYPE_p_IfcUtil__IfcBaseClass, 0);        }

src/ifcwrap/utils/typemaps_in.i

@@ -241,6 +241,28 @@ CREATE_VECTOR_TYPEMAP_IN(std::string, STRING, str)
    $1 = check_aggregate_of_aggregate_of_type($input, get_python_type<double>());
 }
 
+%typemap(in) boost::logic::tribool {
+	if (PyBool_Check($input)) {
+		$1 = $input == Py_True;
+	} else if (PyUnicode_Check($input)) {
+		// we already checked the value of the string in the typecheck typemap
+		$1 = boost::logic::indeterminate;
+	} else {
+		SWIG_exception(SWIG_TypeError, "Logical needs boolean or \"UNKOWN\"");
+	}
+}
+
+%typemap(typecheck, precedence=SWIG_TYPECHECK_INTEGER) boost::logic::tribool {
+    $1 = PyBool_Check($input);
+	if (!$1 && PyUnicode_Check($input)) {
+		PyObject * ascii = PyUnicode_AsEncodedString(result, "UTF-8", "strict");
+		if (ascii) {
+			$1 = strcmp(PyBytes_AS_STRING(ascii), "UNKNOWN") == 0;
+			Py_DECREF(ascii);
+		}	
+	}
+}
+
 %define CREATE_OPTIONAL_TYPEMAP_IN(template_type, express_name, python_name)
 
 	%typemap(in) const boost::optional<template_type>& {

src/ifcwrap/utils/typemaps_out.i

@@ -51,6 +51,10 @@
 			bool v = arg;
 			$result = pythonize(v);
 		break; }
+		case IfcUtil::Argument_LOGICAL: {
+			boost::logic::tribool v = arg;
+			$result = pythonize(v);
+		break; }
 		case IfcUtil::Argument_DOUBLE: {
 			double v = arg;
 			$result = pythonize(v);