In some cases rhev-m changes the hotkey for releasing the mouse grab
to ctrl + alt. This makes it impossible to send ctrl + alt + other-key
to the guest, even when using sticky alt.

What happens is:
-press alt until sticky alt activates
-release alt (but recorded state stays pressed due to sticky alt)
-press ctrl
-hotkey code sees ctrl+alt pressed, releases mouse grab
-mouse grab release code does an unpress all -> end of sticky state.

This patch makes it possible to atleast send ctrl + alt + del (or other key)
using sticky alt. Note: even with this patch it is still a bad idea to
use ctrl + alt as hotkey combi.

This patch stops us from drawing the spice client watermark at the top of
the virtual machine view. We have had requests through several channels to
remove this as it has little added value, and is seen as annoying by some.
Given that we now also have a bugzilla for this I think it is time we really
remove it.
(cherry picked from commit 392ed65dda1a28c85f04ebb09924c6ce83dbdf2b)

For not too old spice-migration, minor is 1.
For older (ancient) spice-migration, minor is 0.

Affects only VM migration while a spice client is connected.

We could introduce another boolean to prevent changes, or just reuse
_active_modifiers_event = true to prevent further update.

Additionaly this patch restore the keyboard state when focusing out,
which is fine when dealing with full remote desktop, but should be
reconsidered if/when SPICE supports remote windows managed by client
window manager for instance, imho.

disable some code that only makes sense when USE_TUNNEL is defined
in client and server channel security level setting.

This one mistakenly had a GPL header rather then an LGPL header.