Updating: moving SMT/Z3 into ATS-Postiats-contrib
Updating: tidying-up a bit
Updating: adding a test for Z3
Updating: adding contrib/libevent
Updating: reorganizing libats-????
Merge branch 'master' of https://github.com/githwxi/ATS-Postiats-contrib
Updating: moved files to the new directory layout