Code review comment for lp:~danilo/launchpad/bug-459132

= Bug #459132 =

This provides scripts/rosetta/fix_translation_credits.py which marks all
existing untranslated credits messages as translated by calling
setTranslationCreditsToTranslated() on each POTMsgSet.

== Implementation details ==

It collects a full list of POFiles and relevant POTMsgSets through
POFileSet.getPOFilesWithTranslationCredits, and doesn't exclude those
which are already translated, though, because of the way
setTranslationCreditsToTranslated is implemented (first check for a
shared message), it works much faster over already translated ones
(tested and confirmed in practice :).

There is a minor change to setTranslationCreditsToTranslated to include
force_shared (so we don't mess up imported diverged and current
translations by accident), along with a new test in test_potmsgset.

The collection method in POFileSet is tested in test_pofile.

Also, full test suite run has completed and there are no test failures.

Script itself is not tested in an automated way, because it mostly
integrates all of the above. Perhaps a small "it runs" test should be
added to make sure privileges are fine.

= Demo & QA =

Run it. Run it on staging.

  scripts/rosetta/fix_translation_credits.py -vvv

= Tests =

  bin/test -vvt test_potmsgset -t test_pofile -t doc.potmsgset.txt

= Lint =

Lint is fine.