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>

Signed-off-by: Ian Leonard <antonlacon@gmail.com>

This adds libnatpmp from old packages and updates it to version
20140401. This new version has to install the header file declspec.h.

libnatpmp is needed for tor.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>