Currently the cache is only invalidated when the datastore changes, while it should rely on selected period of time. Fixes #1659
It is not useful for the RSS feed, as every new entry will be 'yesterday', and it requires an update the next day.
- Heavy refactoring of DailyController - Add a banner like in tag cloud to display monthly and weekly links - Translations: t() now supports variables with optional first letter uppercase Fixes #160
