Merge pull request #39 from qnikst/master

Remove dependency on the deprecated MonadCatchIO-transformers package.
Use pkg-config.
Bump version.
Disable I/O manager on mingw32_HOST_OS.

As suggested in PR #41 (by remdezx) and issue #8, I/O manager calls are
turned into NOPs and the foreign calls to zmq_recvmsg and zmq_sendmsg
are declared "safe".
Bump version.
Constrain `exceptions` to 0.3.*

Fixes issue #42.
Update to `exceptions` 0.4.*
Use `tasty` instead of `checkers`.
Remove upper-bound of `exceptions`.