Implement pagination

[michaelboyles]

Currently, every single comment is loaded when the page load. It would be better if comments cut off after a certain point, with either a 'See more...' button, or maybe a trigger reacting to user scroll, that dynamically loads in the next batch.

In the simple case where every comment has no replies, this is really easy. Just sort by time and divide them into chunks.

When we take into account replies, it becomes harder to determine where the boundaries should be

Foo
 | ---> Reply
          |-----> Reply
Bar 

Think this will likely be related to #16, addressing the nesting problem