package/libsquish: New package

Kodi 15.0 contains an updated version of libsquish:
https://github.com/xbmc/xbmc/tree/master/tools/depends/native/libsquish-native

The OpenElec project provides a separate tarball including the Kodi-
specific patches:
http://sources.openelec.tv/devel/libsquish-1.10-openelec.tar.gz



This patch contains the relevant diff between upstream libsquish 1.13
and the OpenElec tarball.

[Thomas:
 - don't create the usr/lib/pkgconfig directory in STAGING_DIR and
   TARGET_DIR, since libsquish installation doesn't install a .pc
   file.
 - instead, create usr/include and usr/lib.
 - fixup the symlink logic so that the target directory only has a
   symbolic link named after the library SONAME, while the staging dir
   has both usual symlinks: one named after the SONAME, one just
   libsquish.so. Suggested by Yann E. Morin.]

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>