some copy changes on signup, always prompt for repository if none is set
fix edge case in choosing bookshelf modal
add recently viewed repos to select repo modal
remove trailing  from require.js include
some readability cleanups in session.coffee
deal with corrupt data in repo history
use  from  in session.coffe
hide bookshelf history section of 'choose bookshelf' modal if it is empty
add error when selecting a non-existant bookshelf
Merge pull request #134 from oerpub/61939112-choose-bookshelf-on-login

some copy changes on signup, always prompt for repository if none is set