add font, background, light styling.
Merge pull request #29 from calblueprint/ethan/style-login-splash

add font, background, light styling.
created books_groups join table
fixed tabs oops
fixed groups_books table migration to use newer ruby syntax
renamed groups_books table to books_groups
Merge branch 'will/schema' of github.com:calblueprint/worldreader into will/schema