add recent items to frontpage
restyle loans page
show books in blocks (except search)
add tag editor with autocomplete
allow to serve cover images by Google

Conflicts:
	app/helpers/application_helper.rb
	config/application.yml
don't store cover images for Heroku
more flexible sidelinks structure
fit in sidelinks in amsterdam50 theme
improve user profile
fix showing empty lcc field
link book author to search
make isbn validation a more friendly + flash color
do not tag books with remote tags