modplugtools: Added package

This installs the 'modplug123' command line tool to play tracker music
files (MOD, S3M, XM etc.) using libmodplug.

The modplugtools package can build two players: modplugplay that plays
directly via OSS and modplug123 that plays via libao. Since modplugplay
won't work without OSS support and modern kernels are likely to have no
OSS or OSS emulation, we build only modplug123.

If you have a system without ALSA support for some reason, you can
still use modplug123 to play over OSS via libao.

http://modplug-xmms.sourceforge.net/



[Thomas: add missing Config.in comment about the C++ dependency.]

Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>