test, provide regression for bug/19

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, PEBKAC, on unmatched input in dconv(1) always break (regardless of -q|--quiet)

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
test, provide regression for bug/19 (dadd)

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, PEBKAC, on unmatched input in dadd(1) always break (regardless of -q|--quiet)

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
test, provide regression for bug/19 (dround)

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
fix, PEBKAC, on unmatched input in dround(1) always break (regardless of -q|--quiet)

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'bug/19' into next

* bug/19:
  fix, PEBKAC, on unmatched input in dround(1) always break (regardless of -q|--quiet)
  test, provide regression for bug/19 (dround)
  fix, PEBKAC, on unmatched input in dadd(1) always break (regardless of -q|--quiet)
  test, provide regression for bug/19 (dadd)
  fix, PEBKAC, on unmatched input in dconv(1) always break (regardless of -q|--quiet)
  test, provide regression for bug/19