Adding webjars requirejs.
jQuery and Backbone from webjars
spin-js from webjars
typeahead.js from webjars
moment.js from webjars
marked is no longer a views dependency
Removing marked entirely.
Making backbone.projections local.
Making underscore.string local.
Removing require.js optimization, as webjars won't support it until Play 2.3
Removing unnecessary JS files.
Using webjars to manage major JS dependencies.

Should resolve #115 once and for all.
Adding a message when spreadsheets have no associated charts.