WIP copyright statements. See #1082. Also IFCP6 is now IFC4D as we will expand into more 4D apps and widen the scope.

src/ifcdiff/ifcdiff.py

@@ -1,4 +1,23 @@
 #!/usr/bin/env python3
+
+# IfcDiff - Compare IFCs
+# Copyright (C) 2020, 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcDiff.
+#
+# IfcDiff is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcDiff is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcDiff.  If not, see <http://www.gnu.org/licenses/>.
+
 # This can be packaged with `pyinstaller --onefile --clean --icon=icon.ico ifcdiff.py`
 
 import ifcopenshell