mdns GUI launcher

[Antoine Martin]

Follow up from #1332, see also #1333.

Make a GUI that shows all the local servers and let's you connect to the sessions simply by clicking on them.
We may want to differentiate proxy servers from seamless servers, etc.

It would also be nice to be able to type in the password if the session requires one..

[Antoine Martin]

r15349 adds a very basic GUI: I should have done this a long time ago, what a time saver.
Run "xpra mdns-gui" to see all the sessions on the LAN and connect to them with one click.

Still TODO:

• password input somewhere
• block "repopulate" if the user is clicking on something? or just rate-limit it?
• group sessions by UUID, add drop down to select connection method (tcp vs ssh, one IP vs another, etc)
• scrollable view for when there are too many sessions
• handling of proxy servers (and proxy start?)

[Antoine Martin]

mdns gui showing 2 sessions

[Antoine Martin]

• r15350 adds password support
• r15351 shows exit error codes and groups the sessions using their uuid

It's very useful already:

Remaining tasks:

• rate-limit repopulate
• scrollable view
• handling of proxy servers (and proxy start?)
• win32 and osx support: needs pybonjour browsing code (ugly) - or maybe switch to ​python zeroconf instead...

[Antoine Martin]

r15354 + r15355 add support for osx and win32.
One problem is that "zeroconf" relies on netifaces 0.10.4 because of this bug in 0.10.5: ​https://github.com/jstasiak/python-zeroconf/issues/84.
So adding this to the moduleset and win32 setup instructions will be slightly more difficult than usual. (and we'll have to remember to bump both together when fixed)

---

And I don't want to spend too much time on this, so that's probably enough for this release.

@afarr: just a FYI, but if you have mdns enabled on your test servers - this could save you a lot of time. Just run xpra mdns-gui on your client to connect without needing to know the IP addresses and port numbers!
I've uploaded beta builds for osx, win32 and fedora.

[Antoine Martin]

win32 and OSX packaging updated in r15394, with PITA fixups in r15395 + r15396 + r15397 + r15398 (see ticket:1392#comment:4 for details)

[Antoine Martin]

Minor updates:

• r15637 add link from launcher
• r15639 (+ r15641 fixup): build a Xpra_Browser.exe on MS Windows
• r15640 add this to the Windows start menu
• r15643 + r15644 adds packaging of a "Browser" helper for Mac OS
• r15645 was also needed on OSX to detect the subcommand exit code (and needs backporting)

[Antoine Martin]

r15870 fixes ipv6 support, now enabled by default (some of this needs backporting)

[Antoine Martin]

Minor packaging fixes: r15944, r15943, r15940, 15939

[J. Max Mena]

Looks pretty good, noting and closing.

[Antoine Martin]

As of r16852, it doesn't require mdns and can connect to local servers found through their socket files.

[migration script]

this ticket has been moved to: ​https://github.com/Xpra-org/xpra/issues/1334