composer.lock is out of sync, composer.json stability breaks install, install also updated check.php
merged branch stanlemon/2.3-fix (PR #533)

This PR was merged into the master branch.

Discussion
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2.3 install broken, fixes composer.json and updates composer.lock

Current master does not install on a fresh clone, it is broken.  This PR reverts the min stability from "alpha" to "dev" which appears to be the biggest issue.  It also updates the lock file and check.php with fresh versions post "composer.phar update".

Commits
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a0ae2f7 composer.lock is out of sync, composer.json stability breaks install, install also updated check.php
Merge pull request #10 from symfony/master

Merge symfony/standard with Lexance/symfony-multidomain [master]