Ensure that things loaded by server/index.js override addons.

Express will always process the first matching middleware.

A couple examples where this is bad:

* If a proxy was setup, it is always hit before any http-mocks
  you have setup (since it is itself an addon).
* If you want to serve static content (or another express middleware)
  from `server/index.js` you could never handle requests with an accept
  header including HTML. If you did, it would have hit the history state
  addon and just served up `app/index.html`.

In general, it is our policy that the application will always "trump"
addon code.
Merge pull request #2008 from rwjblue/app-wins-express

Ensure that things loaded by server/index.js override addons.
Add blueprint descriptions to ember help generate

Also display '(overridden)' next to overridden blueprints.

Addresses #1237
Addresses #1274

Pass options through printBasicHelp & printDetailedHelp

Hide overridden blueprints unless verbose flag is set

Add example descriptions to built-in blueprints

Add availableOptions to Blueprint
Ensure that startApp helper uses test environment config.
Merge pull request #2011 from rwjblue/ensure-start-app-uses-test-environment-config

Ensure that startApp helper uses test environment config.
Removed broccoli-sweetjs from registry since it doesn't work.

If you try and use it, you'll simply get `Unknown statement type: ImportDeclaration` because sweetjs doesn't know about ES6 modules yet.
Merge pull request #1279 from jgwhite/blueprint-list-description-and-overrides

Add blueprint descriptions to ember help generate
Ensure that `isType` matches if the extension is the type.
Merge pull request #2014 from rwjblue/remove-sweet

Remove broccoli-sweetjs from registry.
[windows] - always split diff using unix line endings

jsdiff always uses unix line endings `\n` which causes tests to fail on
windows because we are trying to split the result based on enviornment EOL
Merge pull request #2015 from raytiley/diff-line-endings

[windows] - always split diff using unix line endings
Add Blueprint.prototype.lookupBlueprint.

Allows custom blueprints to inherit the `files` from another
blueprint without requiring `ember-cli` itself
Merge pull request #2016 from rwjblue/allow-blueprint-to-access-other-blueprints

Add Blueprint.prototype.lookupBlueprint.