Signed-off-by: Gheyret Kenji <gheyret@gmail.com>

https://bugzilla.gnome.org/show_bug.cgi?id=685753

Right now we just start the miner processes, which will just return in
case no matching account is found.
Instead, only run a miner in case we know there's an account of a
certain type configured, and connect to signals for when accounts are
added or removed to check again.

Since it can possibly take very long; use GLib.MAXINT to remove any
timeout from these bus calls.

https://bugzilla.gnome.org/show_bug.cgi?id=687544

These were forgotten from when we switched to the libgd submodule

https://bugzilla.gnome.org/show_bug.cgi?id=687543

This avoids the overview flickering before the preview is loaded, when
launching results from the shell.

Taken from similar code in Boxes.

When we mine remote entries, if their modification time didn't change,
avoid re-querying and setting to Tracker all the other properties, since
it's an expensive operation.
This makes the mining operation much faster.

Instead of making a huge numbers of queries whenever we detect changes
in the graph, batch items in groups, to reduce the workload on the
database.

If the search already has focus, we're going to handle these
automatically; if it doesn't, we don't want to handle them manually,
since they're used for keynavigation.

https://bugzilla.gnome.org/show_bug.cgi?id=669617

Taken from a patch for gnome-boxes by Alexander Larsson.

We derive from GtkClutterEmbed and remove focusability and key event
handling. This means that to Gtk+ it looks like a dumb container
which never gets any key events. This makes Gtk+ keynav work just
like in any other container, although it means there will never
be any Clutter key events. Thats fine though, as we just use
Clutter as a rendering layer.

https://bugzilla.gnome.org/show_bug.cgi?id=669617

This doesn't break string freeze, since we re-use the string from the
toolbar button tooltip.

https://bugzilla.gnome.org/show_bug.cgi?id=684866

https://bugzilla.gnome.org/show_bug.cgi?id=684866

Or it will keep the animation up in the background, keeping the CPU very
busy.

https://bugzilla.gnome.org/show_bug.cgi?id=684726