One-Time Password client (HOTP and TOTP)

* Implements RFC 4226 (HOTP) and RFC 6238 (TOTP)

* Adds sha1.c to apps/plugins/lib (orignally tools/hmac-sha1.c)

* See manual entry for more information

Change-Id: Ia4a4031b29f97361b541e71438aa7f3ea82212f2
9 files changed