use gollum_editor instead of ace
namespace under css ids under birdses_
the user should load the js in his application.js
add id and class to Preview and Submit buttons
render 404 if page doesn't exist.

this fixes #7
JS method calls should end with `()` :bomb:
remove `.parameterize` calls

fixes #2 and #3
replace `/` with `-` in page names

this fixes #6

slashes shouldn't be used in the title of a wiki page, thus they are replaced
with dashes.