This adds support for the integrating libdbus into the lws event loop.
Unlike the other roles, lws doesn't completely adopt the fd and libdbus insists
to retain control over the fd lifecycle. However libdbus provides apis for
foreign code (lws) to provide event loop services to libdbus for the fd.
Accordingly, unlike the other roles rx and writeable are not subsumed into
lws callback messages and the events remain the property of libdbus.
A context struct wrapper is provided that is available in the libdbus
callbacks to bridge between the lws and dbus worlds, along with
a minimal example dbus client and server.
HTTP server protocols have had for a while LWS_CALLBACK_HTTP_DROP/BIND_PROTOCOL
callbacks that mark when a wsi is attched to a protocol and detached.
It turns out this is generally useful for everything to know when a wsi is
joining a protocol and definitively completely finished with a protocol.
Particularly with client wsi where you provided the userdata externally, this
makes a clear point to free() it on the protocol binding being dropped.
This patch adds protocol bind / unbind callbacks to the role definition and
lets them operate on all roles. For the various roles
HTTP server: LWS_CALLBACK_HTTP_BIND/DROP_PROTOCOL as before
HTTP client: LWS_CALLBACK_CLIENT_HTTP_BIND/DROP_PROTOCOL
ws server: LWS_CALLBACK_WS_SERVER_BIND/DROP_PROTOCOL
ws client: LWS_CALLBACK_WS_CLIENT_BIND/DROP_PROTOCOL
raw file: LWS_CALLBACK_RAW_FILE_BIND/DROP_PROTOCOL
raw skt: LWS_CALLBACK_RAW_SKT_BIND/DROP_PROTOCOL
- split raw role into separate skt and file
- remove all special knowledge from the adoption
apis and migrate to core
- remove all special knowledge from client_connect
stuff, and have it discovered by iterating the
role callbacks to let those choose how to bind;
migrate to core
- retire the old deprecated client apis pre-
client_connect_info
