Add checks for programs which are required for the test suite to run.
All prerequisite programs are checked for existance, and if any are
missing,
a list of missing programs is printed, and the test suite is aborted.
All programs currently used in the tests, except those in core-utils,
are checked.
precommit hook
commit hook: acb14030fe0a21b60322c440ad2d20cf7685a376