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>

- Use a temporary file path within the package build directory to avoid
   cluttering the host systems `/tmp` directory.

 - Switch to a gzipped, snapshotted copy of the `oui.txt` file since the
   upstream IEEE server is extremely slow, also fetching an unversioned HTTP
   resource during compilation breaks reproducable builds.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>
[rework to use standard download facility]
Signed-off-by: Etienne CHAMPETIER <champetier.etienne@gmail.com>

- update to latest version (v1.1.2)
 - add license info
 - add myself as maintainer

Signed-off-by: Nicolas Thill <nico@openwrt.org>