Wiki page

## Changes
- Auto complete on input `:author` and `:source`, with jQuery Autocomplete ui
- Create wiki page if it doesn't exist after save a quote
- Simple(I mean no design) wiki page
- Wiki have the parent, sibling and child relationship(using [ancestry](https://github.com/stefankroes/ancestry) gem)

## Screenshots

![Screen Shot 2013-02-10 at 7 36 08 PM](https://f.cloud.github.com/assets/184520/143125/f5be0aea-736d-11e2-8827-7d3b31eaf0c2.png)

![Screen Shot 2013-02-10 at 7 36 53 PM](https://f.cloud.github.com/assets/184520/143126/7ecfc3dc-736e-11e2-94f6-9bb47f3c43a7.png)