scrypt: new package

[Thomas:
  - move from "Libraries -> Crypto" to "System tools", since it only
    installs one binary, scrypt, and no library.
  - bump from 1.1.6 to 1.2.0
  - add comment in the .hash file explaining where the hash is coming
    from.
  - add missing dependency on OpenSSL
  - use BSD-2c as the license code, instead of BSD2
  - use 'main.c' as the license file.]

Signed-off-by: Parnell Springmeyer <parnell@digitalmentat.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>