Added possibility to specify translation contexts
What about introducing the use of msgctxt for ambiguous translations? So translators can better understand how to translate a text.
For example: 'To %s' may have two different translations when used as "Send to recipient" or as "End of a date interval".
The modified web/concrete/elements/permission/duration.php shows a possible implementation.
Merge pull request #673 from mlocati/i18n-context

Added possibility to specify translation contexts