This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
- make sure error messages for bad integers are moderately sensible
- handle test ! "abc" -o "abc" (This should evaluate to true)
(and similar cases) ie:
and/or operator test added to POSIX special case processing.
- more test cases added.
Based on: Work done on 1.x's test(1) by Andrew Moore and Adam David.