If mutter requires the same scale on all logical monitors we must
propagate a scale set on one monitor to the remaining ones or we'll
fail validation leaving users wondering why it doesn't work.
https://bugzilla.gnome.org/show_bug.cgi?id=790809
As the comment hinted at, fixing layouts automatically to ensure their
applicability doesn't actually work in all cases and in fact may force
users to redo their layout completely after a seemingly small change.
So, let's stop pretending we can do it and instead leave it to users
to fix it manually.
https://bugzilla.gnome.org/show_bug.cgi?id=789711
Mutter uses round() while we are just truncating via the implicit
double -> int type conversion, meaning that mutter will reject some
configurations that should work. Fix that by using the same rounding
as mutter.
https://bugzilla.gnome.org/show_bug.cgi?id=786919
Whether a mode is interlaced or not is now exported by adding a
'is-interlaced' (b) value to the mode properties variant. Implement the
is_interlaced() vfunc using this information.
The mode format communicated via the new D-Bus API changed to
specifying modes using a per monitor unique mode ID string. The uint
'flags' was also changed to more flexible a{sv} 'properties' structure.
This adapts as much as possible mutter's new display config API to the
current display panel's expectations. In particular we keep the
concept of logical monitors hidden from the panel. They will later be
exposed when we re-design the panel to make full use of the new API.
https://bugzilla.gnome.org/show_bug.cgi?id=782785
