Update to 4.0.2

CHANGELOG:
4.0.2
* Added `assoc` to `Data.Profunctor.Composition` so that we have all 3 associators.
Add libotr support.
Add patch from http://www.isbear.org.ua/hg/isbear/mcabber-patches/file/tip/use-otr-v4.diff
to fix build with libotr-4.x.