Problem: was not waking writer on HAVE READER

HAVE READER messages from the cluster were being ignored in
pipe_attach_remote_reader, so a waiting writer would time out.
Now the state machine gets a have_reader event so the writer
can send out its waiting data.

Not tested, since I don't have a reproducible case; however it
is fairly obvious, given the detailed logs.

Fixes #68.
Fixed use of includes
Removed failing make check step