Cache language list to prevent look up for each book search
Collapse navbar when clicking log out

Also two unrelated improvements:
Fix invalid css (bg color was set to none rather than transparent).
Focus email field when loading Sign Up or Log In.
Make download a child of detail
Correct items-per-page position when only one page
Add comment explaining the use of modal-___ classes
Merge pull request #150 from andrew-polk/feature/downloadIsChildOfDetail

Make download a child of detail
Merge pull request #144 from andrew-polk/feature/cacheLanguageList

Cache language list to prevent look up for each book search
Merge pull request #146 from andrew-polk/feature/logoutCollapsesNavbar

Collapse navbar when clicking log out
Merge pull request #151 from andrew-polk/feature/fixItemsPerPage

Correct items-per-page position when only one page
Fix missing book title on preflight screen
Merge pull request #147 from andrew-polk/feature/fixMissingBookTitle

Fix missing book title on preflight screen
Display useful message when user has an unsupported browser

This is currently only for IE < 10.
Also display useful message if javascript is unsupported or disabled.
Merge pull request #152 from andrew-polk/feature/detectOldBrowser

Display useful message when user has an unsupported browser