Make menu Zeroconf-aware

[probonopd]

RIght now we display various applications in the menu. Wouldn't it be nice if we could also show for each application's menu entry a submenu with services announced on the network that can be used with this application? E.g., the Printer application would show all printers in a submenu, the Terminal application would show all servers reachable on the LAN via SSH in a submenu, the Browser appliaction would show all websites on the LAN in a submenu, and so on.

This should also automatically make the network services available from Action Search... and remove the need for a separate Zeroconf chooser utility like the one we currently have:

Instead, the "Chromium" menu entry would get submenus for http://Asterisk.local.:8088 etc.

We could then also type aster... into the Action Search box and would get a result that would open http://Asterisk.local.:8088 with Chrome (and each other browser installed):

For this to work, each application would have to specify which Zeroconf services it can handle and for how to invoke the application using the arguments provided by Zeroconf.

[probonopd]

https://github.com/jbagg/QtZeroConf ("please contact me for a copy of QZeroConf with a BSD licence")

Reference:

• https://github.com/jbagg/QtZeroConf/issues/55
• https://github.com/jbagg/QtZeroConf/issues/58

[probonopd]

https://github.com/nitroshare/qmdnsengine is a Multicast DNS library for Qt applications which requires only QtCore and QtNetwork - no other dependencies. No Avahi! No Glib! No (L)GPL! Yay! And it is already in FreeBSD: https://www.freshports.org/dns/qmdnsengine