Added additional LWS_CALLBACK_CLOSED_HTTP callback to just_kill_connection branch of close_and_free_session
add CMake find function for libwebsockets

Signed-off-by: Jiri Hnidek <jiri.hnidek@tul.cz>
Request "send" not to trigger SIGPIPE on errors.
fix http incomplete send handling

Signed-off-by: David Gauchard <gauchard@laas.fr>