clean up Gemfile
use haml for all category views
remove js erb templates
default panel style
show number of errors and explanation message
change ribbon background color for out-of-stock products
clean up css
re-factor admin product views and use haml instead of slim
number errors
adapt alerts and image style
re-factor product_image_tag helper
re-factor image uploader
pass action parameter to category form
adapt product_image_tag parameters in views
remove unused partials