app: add virt_viewer_app_make_dialog()

Add a function to create an application dialog. In the following
commit, we will add more details for connection failures.
app: report disconnection error details

It may be useful to provide more detailed reason for disconnection.

https://bugzilla.redhat.com/show_bug.cgi?id=1115986
Make ctrl-[+-] zoom in/out in fullscreen

Make ctrl-[+-] zoom in/out in fullscreen
with mouse over the control bar.

https://bugzilla.redhat.com/show_bug.cgi?id=987549
Refresh translations from transifex

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Update NEWS for 1.0 release

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Bump version to 2.0 for next dev cycle
spice: avoid crash if connection failed without error

spice_channel_get_error() is not guarantee to return a GError.
Always set ask-quit setting

Avoid creating empty settings files, always set the ask-quit key.

https://bugzilla.redhat.com/show_bug.cgi?id=1006737
Only filter virt-viewer debug messages

Filter only our own debug messages.

https://bugzilla.redhat.com/show_bug.cgi?id=1118365
virt-viewer.xml: remove zoom-{in,out} accelerators

The XML menu accelerators conflict with accelerator set in the code and
prevent using them. This is a regression from d29fc63d.