bump version before release
Disable pipelining again.

CouchDB closes connection after responsding with 409, its not clear
how http client should handle that.
Http client handles the case when the server chooses to close
the connection before sending the response.

The request is retried on a new connection, as for RFC 2616 sec 8.1.4.
This fix is motivated by the actual problem with speaking with CouchDB
server which closes the connection *some time* after responding with 409
status, without giving the headsup with Connection: closed headers.
Tweak the strategy used by http client further.

Make sure that if we are forced to retry a connection, we use a new one.
Retrying disables pipelining and reusing idle connections.
Merge branch 'release-0.25.x'