* GPL3 or later for Readline required
* Otherwise be nice, allow LGPL 2.1 and LGPL 3.0 (similar to Qt)

* The console logger still comes from the RDFSUpdate tool. It cannot
just be relicensed (without permission) and will probably have to be
deprecated/removed.

LGPL build therefore currently *does not yet work* but the basics are in
place for it.