Merge pull request #3019 from sipa/fugbix

Bugfix: nHeightLast instead of nHeightFirst
fix extract_strings_qt.py

- a recent pull changed xgettext to gettext, this is reverted here
Merge pull request #3021 from Diapolo/fix_extract_strings_qt

fix extract_strings_qt.py
Use 'low S' as malleability breaker rather than 'even S'