Provide proper validations for user. Provide translations for user
validation messages.
Add validations to Solution model. Translate error messages.
Add validations to Problem model. Translate error messages.
Reorder translations.
Add validations to Opinion model. Translate error messages.
Add validations to Analysis model. Translate error messages.
Merge branch 'make-sure-validations-are-present-plus-translate-validation-messages'
Make sure author is always assigned.
Merge branch 'make-sure-validations-are-present-plus-translate-validation-messages'