Add pp_host_get_socket_devices_async() and
pp_host_get_socket_devices_finish() functions to PpHost class.
pp_host_get_socket_devices_async() starts searching for socket printer
on given address.
The test consist in connection to the default port 9100 (or the one
given by creator of PpHost) of the address.
We suppose that there is an AppSocket/HP JetDirect printer on the address
if the connection succeeds.
See these links for additional info:
http://en.wikipedia.org/wiki/JetDirecthttp://www.cups.org/documentation.php/network.htmlhttps://bugzilla.gnome.org/show_bug.cgi?id=695564
89fe4eda12