Fix issue where JSON.parse(undefined) throws exception

Observed an error "unexpected token u" on an Android WebView, searched around a little, and discovered JSON.parse with undefined can cause issues on some browsers: http://stackoverflow.com/a/13022566
Update style and revert moving default session initialisation
Merge branch 'master' of https://github.com/cgwyllie/add-to-homescreen into cgwyllie-master
cleanup
Merge branch 'cgwyllie-master'
fix #114