New and improved license rules for #745

Signed-off-by: Philippe Ombredanne <[email protected]>

Author: pombredanne

tests/licensedcode/data/licenses/config.guess-gpl2.txt

@@ -0,0 +1,4 @@
+licenses:
+    - gpl-2.0-plus
+    - gpl-2.0-autoconf
+    - free-unknown