add client example using conduit and lwt
hookup client example
regenerate
spice up demo server with tls certificate and key
Remove build dependency check on `lwt.ssl` for `cohttp.lwt`.
This has been moved to conduit, so only `lwt.unix` is needed here now.

fixes ocaml/opam-repository#3019 failure
bump to 0.12.1
Add sexp onverters for Conduit and Lwt client and server modules
Merge branch 'client-lwt-example' of git://github.com/hannesm/ocaml-cohttp

Conflicts:
	setup.ml
Add `Cohttp_lwt_unix_debug` which lets libraries control the debugging
output from Cohttp.  Previously the only way to do this was to set the
`COHTTP_DEBUG` environment variable at the program start.

This puts a very slight performance hit on the read/write functions
since they need to check the debug variable now, but it's not at all
significant in a localhost test.
Port cohttp_client_lwt to use Cmdliner and be more curl-like
Rename cohttp_client_lwt to cohttp-curl-lwt to match the async version
Add missing cmdliner dep
Travis: install cmdliner
Fix js compilation by adding a sexp printer as well
Bump to 0.13.0 due to the module type change for contexts
disable tests by default
Tweak docstrings for cohttp-curl-lwt
fix hannes' last name!
Merge pull request #208 from avsm/master

Remove build dependency check on `lwt.ssl` for `cohttp.lwt`.