Default App: Onboard

[Jeremy Bicha]

Hi,

Since we intend to default to GNOME on Wayland for 17.10 where
supported by hardware drivers, I nominate removing Onboard from the
default install.

Onboard doesn't work in Wayland (LP: #1672465) and it would be
difficult for it to work there without GNOME Shell being modified to
allow that. See also https://bugzilla.gnome.org/785677

GNOME's built-in Caribou on screen keyboard is not as powerful or
complete as Onboard but maybe it will get better in the next year or
so. Caribou is very well-integrated to GNOME and is already part of
the 17.10 default install.

Thanks,
Jeremy Bicha