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
make phone number and sms optional
do not use phone number for amsterdam50
small submit button code improvement
hide video functionality (until it is complete)
Allow easier debugging during development.
update textual pages
use multithreaded puma on Heroku
amsterdam50 favicon
limit items on home view