Update 2014-05-06

Update packages:

    http-client

Remove packages:

    network-simple
    pipes-safe

Update dependencies from [haskell-core]:

    HTTP
    SafeSemaphore
    conduit
    conduit-extra
    exceptions
    monad-logger
    optparse-applicative
    resourcet
    streaming-commons
    xml-conduit

Signed-off-by: Nicola Squartini <tensor5@gmail.com>