add headers

lib/stitch_plan/color_block.py

@@ -1,3 +1,8 @@
+# Authors: see git history
+#
+# Copyright (c) 2010 Authors
+# Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
+
 from .stitch import Stitch
 from ..threads import ThreadColor
 from ..utils.geometry import Point

lib/stitch_plan/stitch_group.py

@@ -1,3 +1,8 @@
+# Authors: see git history
+#
+# Copyright (c) 2010 Authors
+# Licensed under the GNU GPL version 3.0 or later.  See the file LICENSE for details.
+
 from .stitch import Stitch