clean up test output

- removed a few remaing places where output wasn't being passed
  through echo_i or cat_i
- added a "digcomp" function to conf.sh.in to send digcomp.pl output
  through cat_i and return the correct exit value
- set SYSTESTDIR when calling echo_i from nsX directories, so that
  the test name will always be printed correctly
- fixed a test name typo in conf.sh.in
4 jobs for test-output in 11 minutes and 17 seconds (queued for 11 seconds)
Status Job ID Name Coverage
  Build
passed #2568
linux docker
build:debian:sid:amd64

00:05:05

passed #2569
linux docker
build:debian:sid:i386

00:05:29

 
  Test
passed #2570
linux docker
test:debian:sid:amd64

00:05:36

passed #2571
linux docker
test:debian:sid:i386

00:05:46