Add support for explicit closures (thanks gershomb)
Additional raw message handling primitives
Merge branch 'development' into explicit-closures
Merge branch 'explicit-closures' into development
Silence some compiler warnings
Additional warning in the comments
Expose NodeId’s constructor and introduce matchSTM

Various clients need to construct NodeId’s, notably all the various
CH backends, so it needs to be public. Also provide a match primitive
that can be used to compose STM actions with the receive family of
functions.