Initial implementation of the module unification feature flag

[mixonic]

Quite barebones and very much a WIP. The mentioned instructions should be helpful for smoke testing:

# Install Ember-CLI canary globally:
npm install -g ember-cli/ember-cli
# Create a new app with the module unification blueprint
ember new my-app -b ember-module-unification-blueprint

@iezer is following up to push a commit with further tests for the RequireJS ModuleRegistry.

[mixonic]

This line must be changed before merge. It defaults the FF to true when what we want is: true only if configured or when running tests.

[mixonic]

I believe this dependency is not required.

[mixonic]

Additionally ember-cli should be version 2.13.0-beta.2. There is code in index.js which is run when the feature flag is enabled (which it should be for tests, but not for tests on older versions of Ember).

[rwjblue]

this is incorrect, babel 6 does not have a blacklist like this