0.6.0

• An answer is written by the fiber that flushes it, where every flush was handed to a writer fiber of the connection's own and waited for: a send is one write, with no fiber woken and no promise to wait on, and a deadline moves by writing an int, where it boxed an Mtime.t each time. Sending to many clients at once leaves far less for the collector to promote -- delivering an event to ten thousand subscribers costs about a third less CPU -- and a plaintext answer about an eighth less. A write the socket refuses ends its connection without another attempt. A takeover is still handed a Buf_write.t with a fiber that copies it.
• spindle-postgres is pinned to rowtype 0.8.0, its latest release, where it was pinned to 0.7.0.