Merge pull request #224 from APSL/master

Remove the http protocol from cdn scripts.
Add MODELTRANSLATION_LANGUAGES setting.
Describe use-case for MODELTRANSLATION_LANGUAGES
Merge pull request #226 from leplatrem/patch-1

Describe use-case for MODELTRANSLATION_LANGUAGES.
Use AVAILABLE_LANGUAGES do detect missing fields
Merge pull request #227 from leplatrem/use_available_languages_for_sync

Use AVAILABLE_LANGUAGES do detect missing fields