add Query, QueryBook, and Book models
validate book isbn, title, author
checkboxes for deselection of individual books
checkboxes using check_box_tag rather than book_id.check_box
add Book only if not already in db and allow selection of individual books
forgot to uncomment line disabled for testing
add xisbn lookup of alternate editions
look up alternate editions using Google Books api
xisbn alternate editions with title, author, language, year
xisbn editions into Edition fields in db
rename query route to editions
view for selection of editions
add selected editions to db as query_editions
sort editions by year
amazon api price lookup testing
half api listings lookup testing
two-column book and edition layout
add HalfListing and HalfSeller
save half_listings and half_sellers in query handler
render query showing listings grouped by seller