Merge pull request #1 from pi-engine/master

update trunk Pi master
Default theme style refactoring
Code cleaning up
Refactored view helpers to allow for attributes: Backbone, Bootstrap, Css, JQuery, Js
CSS class/ID name standardization in process: prefixed with "pi-" and module identifier
Fixed typos for asset canonization
Default theme refactor in process
Organized theme CSS to style.css for generic, front.css for front pages and admin.css for admin area
CSS CS in process
Fixes dependency of backbone and underscore
Build User APIs with avatar factory
Merge pull request #2 from pi-engine/master

update with Pi Master
Update Font Awesome 3.2.1
Added syntactic sugar for escaper: '_escape' in lib/Pi/Utility/Filter.php
Fixes bug for guest account wakeup
Added escape for HTML attributes
Changed theme error-exception.phtml to error.phtml
Changed Pi::register('user') to Pi::service('user')->getUser()
Added mising style for layout-simple
Added syntactic sugar for user service: Pi::user()