new dialog/libdialog testing

[David Boyd]

Having some time to test 9.0-CURRENT with the new dialog command has
uncovered only one major omission (for us): prgbox/dialog_prgbox.

This is used in most (if not all) of our installation/management scripts.

Was prgbox omitted for any particular reason?

I realize that change is inevitable.

Is there a better approach to running a program in a window?

We like many of the new features presented, but are wary of problems down
the road due to the omission of prgrbox.

I notice that sysinstall uses dialog_prgbox in 8.1-RELEASE.