THRIFT-1743: Add composer.json for new Symfony 2.1 Dependency Manager

From acba5ca4cb9d6d727e63b25a6ce8dfaf863190bc Mon Sep 17 00:00:00 2001
From: Mauro Maggi <mauro.maggi@immobiliare.it>
Date: Fri, 28 Mar 2014 17:18:30 +0100
Subject: [PATCH] Adds composer.json for Thrift dev-master branch and aliases
 dev-master to 1.0.x-dev

Github Pull Request: This closes #91