Provide selftests for all crypto algorithms

Provide crypto selftests for all algorithms:

• apis:
  • gnutls_hmac_fast
  • gnutls_hash_fast
• ciphers:
  • null
  • arcfour-128
  • 3des-cbc
  • aes-*-cbc
  • aes-*-ccm
  • aes-*-ccm_8
  • aes-*-cfb8
  • aes-*-gcm
  • arcfour-40 [not implemented]
  • rc2-40-cbc
  • camellia-*-cbc
  • camellia-*-gcm
  • salsa20-256
  • salsa20/r12-256
  • chacha20-poly1305
  • gost28147-*-cfb [5 paramsets]
  • xxx-pgp-cfb [9 ciphersuites, not implemented]
• digests:
  • null
  • rmd-160
  • md2
  • md5
  • md5-sha1
  • sha1
  • sha-2-224/-356/-384/512
  • sha-3-224/-256/-384/-512
  • gostr-94
  • streebog-256/-512
• macs:
  • null
  • rmd-160
  • md2
  • md5
  • md5-sha1 [placeholder, not implemented]
  • sha1
  • sha-2-224/-356/-384/512
  • sha-3-224/-256/-384/-512
  • gostr-94
  • streebog-256/-512
  • sha3-* [reserved, not implemented]
  • umac-96/umac-128
  • aes-cmac-128/-256
• pk:
  • rsa
  • rsa-pss
  • dsa
  • dh
  • ecdsa
  • ecdh-x55519
  • eddsa-ed25519
  • gost-01
  • gost-12-256/gost-12-512