Update to 0.12.2.2

changes:
0.12.2.2
  - Merge pull request #20 from kazu-yamamoto/master
    stop using reproxy.
    GHC 7.8 provides Data.Proxy and "tagged" will stop exporting its Data.Proxy. Unfortunately, GHC 7.8's Data.Proxy does not have "reproxy".
  - Merge pull request #19 from singpolyma/master
    Export the non-IO key generators again.

0.12.2.1 ( 0.12.1 --> 0.12.2.1 )
  - lambda

0.12.1
  - Add keyLengthBytes tag.
  - Add a new i2bs_unsized (by request)