Import Acme demo bundle from symfony standard edition
feature #119 Import Acme demo bundle from symfony standard edition (romainneutron)

This PR was merged into the 3.0.x-dev branch.

Discussion
----------

Import Acme demo bundle from symfony standard edition

See https://github.com/symfony/symfony-standard/issues/639
This allows to install the Acme demo bundle on project creation (default to false)

Commits
-------

9e806a9 Import Acme demo bundle from symfony standard edition