warning cleanups, handle exception in accept#376

Merged

hannesm merged 3 commits intomirage:masterfrom hannesm:tests

Nov 16, 2018

+56-55

Commits on Oct 6, 2018

omit warning -3 in segment and user_buffer (deprecated Lwt_sequence); fix warnings in test
hannesm
committed

Commits on Oct 9, 2018