Add a Paginatable module

This can be mixed in to array-like instances.

Tested-by: Mark Somerville <mark@crocodile.is> [Arch, MRI 2.1.1]
Signed-off-by: Mark Somerville <mark@crocodile.is>
Paginate the photo lists

Tested-by: Mark Somerville <mark@crocodile.is> [Arch, MRI 2.1.1]
Signed-off-by: Mark Somerville <mark@crocodile.is>