multiplexing a web server through the same port as the xpra server

[Antoine Martin]

Similar to #426, but this will allow us to only intercept xpra packets, regular packets can be forwarded to a web server which can respond to regular HTTP packets.

immediate benefits:

• a scan will show the port as belonging to the web server and xpra remains hidden
• we can server an html5 client page (#473) through the same server port

[Antoine Martin]

PoC patch which does the multiplexing for http get requests only in "ServerBase?"

[Antoine Martin]

r4948 implements this and will allow us to do #473 much more easily.

Here's how to test:

• start a web server on port 8000:

  thttpd -p 8000
  

• verify you can browse to it:

  xdg-open http://SERVERIP:8000/
  

• start an xpra server with the tcp proxy option pointing to this web server we have just started:

  xpra start :10 --bind-tcp=10000 --start-child=xterm --tcp-proxy=127.0.0.1:8000
  

• verify you can attach to this server:

  xpra attach tcp:SERVERIP:10000
  

• verify you can hit the web server on this same port, ie: open your browser at:

  http://SERVERIP:10000/
  

[Smo]

Tested on Fedora 19 and Fedora 20 x86_64 with no issues.