Feature/mie 1337 require.js build changes to remove hardcoded id

Separates the require.js's configuration (now lives in config.coffee) from the initialization (main.coffee) of the module in order to remove the user's hardcoded id from the build file. We also added 'ActivityStream' as a separated module.

The example instanciation of this module was moved to app/index.html

Ooh good call. We should change this in develop, since it is already there and update this branch with develop.