Merge pull request #33 from jonkri/master

Add some `Jid' utility functions; don't allow construction of `Jid'
avoid direct use of PU constructor

Building picklers from predefined combinators is more robust against possible future API changes.
Merge remote-tracking branch 'upstream/master' into upstream
remove to prefix from toLocalpart, toDomainpart and toResourcePart
quell ghc warnings
check for roster versioning stream feature and disable roster versioning unless present
drop outbound stanza buffering

Stanza send functionality now directly sends the stanzas over the wire and returns appropriate notification whether the sent succeeded (as far as we can tell)
add support for non-standard options element in roster versioning stream feature
Cap `bytestring' dependency

For some reason, `bytestring' versions above 0.9.2.1 causes (at least)
GHC 7.0.1 to panic, so I capped the version while investigating the
issue.
Specify and mention `cabal-install' dependency

The `cabal-install' dependency needs to be at least 1.14 so that the
build of `lifted-base' will not fail with an "unrecognized option:
--disable-benchmarks" error.
Stream.hs: Add `tryIOError', not available in `base-4.2'