It's been removed.

https://bugs.freedesktop.org/show_bug.cgi?id=78376

Conflicts:
	configure.ac
	libempathy-gtk/empathy-chat.c

+ merge updated translations from master

We don't have to wait for backlog to be inserted before adding
pending messages anymore since backlog are prepended in the view.

https://bugzilla.gnome.org/show_bug.cgi?id=662672

+ TpawAvatarChooser: adapt for tp_account_dup_avatar_async

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=77144

Bug: https://bugzilla.gnome.org/show_bug.cgi?id=727162

The ubuntu-online-accounts parts are untested, and might not even
compile.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=76828

We previously used ListNames, but GetNameOwner is simpler.

We don't need to fix this right now, strictly speaking, but it's good
to get rid of libdbus where we can.

Building with LDFLAGS=-Wl,-z,defs reveals that libempathy-gtk
and libempathy rely on the host application to link to cheese and udev.
This is because the telepathy-account-widgets convenience library
does not pass its dependencies through, which appears to be deliberate
(commit da8acc15 in tp-a-w).