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

I'm completely agree, but I think, adding fixtures should be done in another branch as another feature based from develop branch.
The id here, was moved here from app/scripts/main.coffee. This PR is about creating the build file properly. The id is now in the index.html (used for testing) instead of main.coffee which is used to build the final script.