fix path handling for subdir mounting (fixes #13)

`config.action_controller.relative_url_root` can be used to tell Rails
that you are deploying to a subdirectory. The default is
`ENV['RAILS_RELATIVE_URL_ROOT']`.

the asset pipeline doesn't like using the value from request script_name,
although this should contain the correct value and should theoretically
be possible :(
css fixes: typo, duplicates, pre/code should be visible in preview too, remove font for comments

 * the comments should use the same font as the page they are embedded in
fix redirect_back: RedirectBackError needs namespace
Use common api javascript/css as assets

 * assets can be cached forever (checksummed filenames)
 * users can overwrite css by including an element with id="juvia-api-css"
 * removed include_base and include_css
Add FastCGI support
update bundle; rails ~> 3.1.12
custom style
migrate to rails 3.2
rails 4.0, update devise, fix secret token handling, fix spec tests