Issue 1258: photo albums are not complely themeable with photo_album.tpl

This moves some html code from /mod/photos.php to photo_albums.tpl. It based on the red commit https://github.com/friendica/red/commit/df70c2c9b62365c9b0feb8a482aef1ac626fabd6 .

I have very very little coding skills. That's why it should be reviewed very carefully. I tested it on my own friendica installation and there it works.