[dtaht/Cerowrt-3.3] 9b9dc1: [build]: add signing support

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dtaht/Cerowrt-3.3
  Commit: 9b9dc1dccdc50089e6cb68ddfd5a9711063f2f7a
      https://github.com/dtaht/Cerowrt-3.3/commit/9b9dc1dccdc50089e6cb68ddfd5a9711063f2f7a
  Author: Stephen Walker <stephendwalker+github at gmail.com>
  Date:   2012-06-16 (Sat, 16 Jun 2012)

  Changed paths:
    M Config.in
    M include/image.mk
    M package/Makefile
    M package/opkg/Makefile
    A package/opkg/files/opkg-curl.conf
    A package/opkg/files/opkg-gpg.conf
    A package/opkg/files/opkg-smime.conf

  Log Message:
  -----------
  [build]: add signing support