minor, sketch out terms tool with custom char ranges

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, unify old terms and terms-tst tools, so now custom char classes can be specified

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, support named sets a la tr(1) in terms(1) util

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'tool/terms'

* tool/terms:
  minor, support named sets a la tr(1) in terms(1) util
  minor, unify old terms and terms-tst tools, so now custom char classes can be specified
  minor, sketch out terms tool with custom char ranges