Merge pull request #28 from camilotorresf/pin-loaders-requirements

Pin loaders requirements
Pin loaders: create fields for price and image url
Pin loaders: adds price to forms
Pin loaders: fix price field in edit dialog
Pin loaders: show price in item list
Pin loaders: show original image in blank tab
Pin loaders: fix edition of tag
Pin loaders: price is optional
Pin loaders: formats the price before inserting
Pin loaders: add a product url required field
Pin loaders: notification of added items across the top
Pin loaders: adds a button to load more if neccesary