Proposal: replace jekyll-paginate with octopress-paginate

Hello there!

[jekyll-paginate](https://github.com/jekyll/jekyll-paginate) by @parkr is no longer under active development:

> Feel free to build it, test it, and share widely. I worked on an idea in #22 but I just can't get excited about pagination. My vote is to kill off this version and move in a new vision that is as easy as possible to use, but still flexible.
> – @parkr

And that's exactly what @imathis developed: [octopress-paginate](https://github.com/octopress/paginate)

It's backward compatible plugin with [jekyll-paginate](https://github.com/jekyll/jekyll-paginate) but offers more possibilities, like the ability to paginate collections :)