translations: automated XML upkeep
Merge pull request #335 from xylographe/upkeep

translations: automated XML upkeep
Fix for #336 (auto-break)
Merge branch 'master' of https://github.com/SubtitleEdit/subtitleedit
nl-NL translation: minor corrections/improvements + new tags
nl-NL translation: spcorr + experiment (buttons)
nl-NL translation: preferences 1