Added ability to show time interval between photo date and now.
Still writing category for UIViewController in order to share photos in different controllers.
Problems:
1. Aforesaid category needs delegate and its method for mail_controller.
2. 'cell.selected=NO' doesn't work properly in PSStreamController (cells are selectable with grey background color)
3. If cell cannnot display an image ('like butterfly') - it takes some reusable cell with its image and display it.