0.9.12

0.9.12 (2013-11-28):
* Improve documentation for `Cohttp.Header`.
* Expose Fieldslib setters and getters for most of the `Cohttp` types (#38).
* `Cohttp.Set_cookie.t` is no longer an abstract type to make it easier to update (#38).
* [Lwt] ignore SIGPIPE unconditionally if using the Lwt/Unix module (#37).
* Rename `Cookie` creation parameters for consistency (interface breaking, see #44).
* Fix transfer-length detection (regression from 0.9.11 in #42).
* Add Merin editor file (#41).