[ykpers/el6] (6 commits) ...Merge branch 'master' into el6

[Dennis Gilmore]

Summary of changes:

  a9ce0a6... - build with libusb on s390(x) (*)
  5a4c680... - Add support for new features in YubiKey 2.2. - Stricter a (*)
  0a9fa89... fix build on big endians and with default unsigned char (li (*)
  95ca53a... Update to upstream version 1.6.0 (support for firmware 2.3. (*)
  46d568f... Rebuild for rpm-4.9.1 trailing slash bug (*)
  2a75583... Merge branch 'master' into el6

(*) This commit already existed in another branch; no separate mail sent