Experimental support for Windows Named Pipes control socket

[zobo]

No description provided.

[derickr]

I am generally OK with this idea, but I think I would like to see the following changes:

1. define a new HAVE_CTRL_SOCKET_SUPPORT flag, either in the config.m4/config.w32 script, or otherwise in php_xdebug.h — this prevents the #ifdef __linux__ | WIN32 shenanigans (which is not really descriptive)
2. I think the Windows specific code should not be in ctrl_socket.c, but rather in ctrl_socket_named_pipes.c (and extracting the specific Unix socket code from ctrl_socket.c into a new ctrl_socket_unix_socket.c file). handle_command and the CTRL_FUNC(…) functions can remain. The other common interfaces can be called from the functions already existing in ctrl_socket.c (i.e., xdebug_control_socket_setup calls xdebug_control_socket_named_pipes_setup and xdebug_control_socket_unix_sockets_setup), etc.
3. How do we do tests? I don't know, but I would like to have some. :-)