Added nls.mk as this is now required.

Fixed license information.

Several small fixes and cleanups.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

The CONTRIBUTING.md requests an (or multiple) SPDX identifier for GPL
licenses. But a lot of packages did use a different, non-SPDX style with a
"+" at the end instead of "-or-later".

Signed-off-by: Sven Eckelmann <sven@narfation.org>

Signed-off-by: Peter Denison <openwrt@marshadder.org>

Adopt the package from the oldpackages repo at https://git.archive.openwrt.org/$
Update to version 2.3.10 (released Nov 2016)
Update source URL
Depend only on GLib2, not glib1.2

Signed-off-by: Peter Denison <openwrt@marshadder.org>