Merge pull request #3 from lpsmith/master

Use unsafe calls to c
add support for unreleased byteSwap functions that I added to ghc 7.8
Added cbits and System.Endian fns for Word16
Merge pull request #5 from ImAlsoGreg/master

Added cbits and System.Endian fns for Word16
Conditionally compile cbits/endian.c

Also added to Extra-source-files so that cabal sdist is guaranteed to
work no matter which version of GHC you happen to be using at the time.