Revision 1869338

mod_proxy: factorize mod_proxy_{connect,wstunnel} tunneling code in proxy_util.

This commit adds struct proxy_tunnel_rec that contains the fields needed for a
poll() loop through the filters chains, plus functions ap_proxy_tunnel_create()
and ap_proxy_tunnel_run() to respectively initialize a tunnel and (re)start it.
 
Proxy connect and wstunnel modules now make use of this new API to avoid
duplicating logic and code.