minor, do probing for columns in co_tser_rdr()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
chore, remove no-symbol option again, instead use co_tser_rdr() probing feature

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, rewrite step finder so that special symbol .u==0U can be found

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, adapt offset getters in rpaf system and str-interner too

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, don't bother writing the special NOSYM symbol in co_echs_out()

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
test, adapt roll-over regression tests to changed co_echs_out() behaviour

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

* cmd/flow:
  test, adapt roll-over regression tests to changed co_echs_out() behaviour
  minor, don't bother writing the special NOSYM symbol in co_echs_out()
  minor, adapt offset getters in rpaf system and str-interner too
  minor, rewrite step finder so that special symbol .u==0U can be found
  chore, remove no-symbol option again, instead use co_tser_rdr() probing feature
  minor, do probing for columns in co_tser_rdr()