= can: make client connection actors actively close the connection after completion of a `Connection: close` response
= can: remove active connection closing from HttpHostConnectionSlot (now in client connection actor)
= can: prevent `Received illegal response` warning after regular PeerClosed events, fixes #350
= io: speed up BackPressureHandlingSpec by factor of 10 (from 20s to 2s)
= can: small improvement in SprayCanServerSpec
Merge pull request #356 from spray/wip/ticket-350-and-more

Fix for #350 (erroneous `Received illegal response` warning in spray-can client), smaller improvements