Nested Albums

*NOT READY FOR MERGE, LOOKING FOR GUIDANCE*
I'm working on adding a `parent_id` to the album object, allowing albums to be nested.  Simple use case is something like having a parent album called "Family", and sub albums called "Immediate" and "Extended".

The PHP is coming along well, though I'm having a hard time figuring out how to view templates work.  My thought was to have an Albums section listed at the top (if any subalbums exist), and show all photos below.  Kind of like how there are "Smart Albums" on the index page.  Any pointers on where to look/edit?  I'm good with editing JS, but apparently my template-fu is weak.

Also, I realize that I need to change from spaces to tabs, and that will be completed before this PR is fully ready.