Add libnice as a plugin. If it is present, use libnice to enumerate
local IP addresses and listen on them to support direct connections for
Jingle SOCKS5.
Tested with Conversations and Gajim.
Created the nice.vapi file using
```
vapigen --library nice --pkg gio-2.0 --metadatadir metadata /usr/share/gir-1.0/Nice-0.1.gir
```
It's barely possible for .onion servers to provide a non-self-signed cert. But that's fine because encryption is provided independently though TOR.
see #958
* Move to GNetworkMonitor
Dino currently talks to NetworkManager over DBus to know the state of
the network.
That doesn't work in a Flatpak sandbox by default though, because
Flatpak filters DBus communications and only allows a very small set of
things to pass (which are known to be safe).
Gio provides an API to know the state of the network (and be notified of
changes via a signal): GNetworkMonitor.
And GNetworkMonitor works both inside a Flatpak sandbox, and in
traditional builds. (in Flatpak it uses what we call a "portal", which
are the clean, safe way to let apps exit their sandbox)
Fixes#235
* Don't check for network connectivity for now
The connectivity check really is the correct thing to do:
* network_available means that the computer has network routes to
"somewhere". That is, it is connected to a router.
* connectivity.FULL means that the computer can access "the
Internet". That is, if it is behind a router, that router is
connected.
As a result, only checking for network_available is not correct.
Unfortunately, NetworkManager tends to wait a long time before checking
for connectivity. As a result, it is possible that a transient network
error leaves NetworkManager thinking that network_available is true but
connectivity!=FULL, and it will wait several minutes before realizing
that the Internet connexion did come back.
During that time, apps checking for connectivity (e.g the whole GNOME
desktop) will think they don't have access to the Internet, while apps
that don't (e.g Firefox) will access the Internet just fine. Users are
understandably confused when that happens.
Removing the check for connectivity is an acceptable trade-off in the
short-term, until this situation is improved on the NetworkManager side.
https://bugzilla.gnome.org/show_bug.cgi?id=792240
Xavier Del Campo Romero
fiaxh