cleanup app.js

separated functions in different files
added foo.init(app) functions for initial (and repeated loading)
added foo.add_route(path,app) for extending app with routes

- channels.js - load channels from spreadsheet, add routes for voting
- contributors.js - load contributors from spreadsheet
- page_handling.js rewrite of pages that have ejs markup
- versions.js - neo4j-version loading from github and merge with defaults
- videos.js - loading of videos, categorization, adds related to video-pages, videos to content.videos
- meetup.js add route
- munchkin.js add route