Add time range to dataset and entry controller views. This will only show on dataset view pages (they can return entries page with time range).
Added created and modified timestamps for the dataset on its about page.
Added tests for timestamps (both on about page and on the view page)
Remove sort function based on members() and do a single db query instead
Test fixes. Missing from key in dataset on view page and since time format is now dates (no text) tests have been updated to reflect that.
Fixed a type fodr -> for
Merge pull request #630 from openspending/618-date-range

Date range