0.3.0

• Breaking: every duration is an Mtime.Span.t named for what it bounds, not a float of seconds named for its unit, so a wait in the wrong unit no longer compiles. connect's and Listener.connect's ?timeout_s is ?timeout, Listener.connect's ?heartbeat_s is ?heartbeat, Pool.create's ?timeout_s, ?wait_s, ?max_lifetime_s and ?idle_check_s are ?timeout, ?wait, ?max_lifetime and ?idle_check, and Pool.use's ?wait_s is ?wait: write ~timeout:Mtime.Span.(10 * s).

• Breaking: timeout_s is timeout, and set_timeout takes ~timeout:Mtime.Span.t option.

• Breaking: the Conninfo.t field connect_timeout_s : float option is connect_timeout : Mtime.Span.t option. The connection string still gives it in whole seconds, as libpq reads it, and to_url writes it in whole seconds, rounded up. Only a zero span now falls back to the connection's timeout, since a span is never negative.

• Breaking: abandon and resume are gone. The pool has stopped a cancelled borrower through Eio cancellation since 0.2.0, and nothing else called them. To stop a statement, cancel the fiber running it: the statement is cancelled at the server and the connection closed.