add en-GB and tr to the list of supported languages
add en-GB, tr and zh
remove unused strings
update all translations from Glotpress
Merge branch 'develop' into issue/1292-update-translations
fix typo in nux_help_description
Merge branch 'develop' into issue/1292-update-translations
remove broken html formatting in translations
Merge pull request #1304 from wordpress-mobile/issue/1292-update-translations

fix #1292 update translations and add new languages: en-GB, tr and zh-TW