[AD] Resizeable windows

["Peter Hull" <peterhull90@xxxxxxxxxx>]

What's the plan for resizeable windows?

There could be either
A flag (AL_RESIZEABLE) to al_create_display and an event to tell the
app it's been resized
or
An event which is a request for a resize, which a compliant app would
respond to by calling al_resize_display* If an app doesn't want to
resize it just ignores this message.
or
No resizing at all

I prefer option (2) I think.

Pete

* whatever it will be called