refactor error displaying
refactoring folder upload step 1

- extract folder modal in a class
Modal Refactoring
- factor out Modal error usages into Modal.error
- new FolderModal every time
- extends events
extract upload moda into its own class
fix modal afterRender
bugfix modals & spinner
user ModalUpload to upload files in a folder
brunched
Merge remote-tracking branch 'cozy/master' into aenario/master

Conflicts:
	client/app/initialize.coffee
	client/app/views/files.coffee
	client/app/views/folder.coffee
	client/app/views/styles/_main.styl
	client/public/javascripts/app.js
	client/public/javascripts/app.js.map
	client/public/javascripts/vendor.js
	client/public/javascripts/vendor.js.map
	client/public/stylesheets/app.css
	client/public/stylesheets/app.css.map
missed conflict
fix spinner
use 404 for missing folders too
brunched & built
Merge pull request #61 from aenario/refactoring/upload-foler

improve Upload modal