[AD] thoughts on a release

[Peter Wang <novalazy@xxxxxxxxxx>]

So, activity on 4.9 been a bit low for a few months.  Probably everyone
has more interesting things to do.  Perhaps the library is in pretty
good shape.  I have been wondering if we should seriously consider
making a 5.0 release soon, i.e. in a few months.

*If* we were to do that, what changes would be critical to you?
What features would you be happy to put off?  Note that Allegro 5.2
doesn't have to be a long time in coming, but nor is it guaranteed that
5.2 would ever come out.

I'll start.

- al_get_errno/al_set_errno are not used consistently yet.  I suggest
  hiding them as private functions until the work is completed.

- The custom memory management functions are also not used consistently,
  and may be put off for later.

Peter