ignore when breaking text into runs for display, and implement setting this
on Mac (other ports just use 0xffffffff).
We don't use DeviceLoop for this any more because Apple Technical Q&A
QA1024 says we shouldn't. Unlike their example, we don't depend on the
Display Manager's being present either.
[originally from svn r2264]
This doesn't include any mkfiles.pl glue, and is missing one or two other
fixes. The terminal emulator is kind of working, though, as, I believe, is
the store module. Everything else is yet to be done.
[originally from svn r2226]
