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>

fix Makefile chmod (644)
replace MD5SUM with HASH
add PKG_MIRROR_HASH when PKG_SOURCE_PROTO:=git

(PKG_SOURCE_PROTO:=svn tarballs are not reproducible for now)

Signed-off-by: Etienne Champetier <champetier.etienne@gmail.com>

We can just set GREP and SED in the configure command instead of fixing up
the paths using sed afterwards. This makes the build more robust (and we're
currently preparing a change of the host staging dirs in LEDE that might
break this otherwise).

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>

Switch to xz tarball

Signed-off-by: Daniel Engberg <daniel.engberg.lists@pyret.net>

GNU libtool is used to ease the usage of shared libraries in Makefiles.

The new package libtool-bin contains the script libtoolize which is used
to prepare a package to use libtool.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>