Extracts CoreObject into a separate library.

This is a first step towards the direction of splitting `ember-cli` into
micro libraries. `CoreObject` now lives under
[stefanpenner/core_object](https://github.com/stefanpenner/core_object).
Merge pull request #1752 from twokul/core-object

Extracts CoreObject into a separate library.
Update broccoli-concat.
Merge pull request #1757 from rwjblue/update-broccoli-concat

Update broccoli-concat.
Bring back .bowerrc file.

This makes upgrades much easier, and prevents issues with bower
searching an applications parent directories and finding an unrelated
`.bowerrc` file that has a directory directive.
Update broccoli-concat.

Ensures the tmp directory is cleared properly.
Merge pull request #1766 from rwjblue/ensure-build-is-cleared

Update broccoli-concat.
Merge pull request #1761 from rwjblue/keep-bowerrc

Bring back .bowerrc file.
fool-proofing the generated README.md
Merge pull request #1768 from ccoenen/readme

fool-proofing the generated README.md
Ensure imported assets are watched if they exist on disk.
Merge pull request #1774 from rwjblue/ensure-imported-files-are-watched

Ensure imported assets are watched if they exist on disk.
Ensure postBuild hook is called for `ember build`.
Merge pull request #1775 from rwjblue/ensure-build-calls-post-build-hook

Ensure postBuild hook is called for `ember build`.
fix ember init command in empty directory
Watch config/environment.js and export app-name/config module.
Merge pull request #1777 from rwjblue/watch-config-env

Watch config/environment.js and export app-name/config module.
Update CHANGELOG.
Remove debugging logging.
Fix `tests/index.html` to remove `{{ENV}}` references.