Use console events instead of replacing the console application

As mentioned in #23, with the console events from symfony 2.3 there is no need to replace the console application.

Instead of using --jms-job-id the RunCommand now sets an env variable, "jmsJobId", which is evaluated in the ConsoleListener.
The ConsoleListener listens on all three ConsoleEvents, COMMAND, EXCEPTION and TERMINATE.
On COMMAND it adds the tick function, which adds statistics to the job, if statistics are enabled.
On EXCEPTION it writes exception information to the job.
On TERMINATE it writes memory usage information to the job.

Tested it with PHP 5.5 on Mac OS and Windows.
Travis builded successful with 5.3, 5.4 and 5.5, see https://travis-ci.org/temp/JMSJobQueueBundle

I also did a few bugfixes, removed duplicates from composer.json, switch to minimum-stability stable, and of course raised the symfony/framework-bundle requirement to 2.3. In my oppinionen, since this is a long term support version, the raised version shouldn't be a problem.

I did NOT commit a new composer.lock, since this would've raised everything to 2.5.
But composer install worked fine, I got the correct versions.