Merge pull request #9 from mploigt/feature/redesign

Added tabs to edit/add forms and CSS updates
merge latest
Adding media class Mime
re-structure bootstrap
add new validations to BaseModel
rewrite BaseController::_upload()
Adding Assets Model
update import.js to fit to new file-upload structure
adding AssetsController and custom views for a start
adding import Converter
Adding more options to Assets
Working on improved import/export
showing content of import-files on assets
fix file-upload on scaffold import