Here are the new simplified rules:
* Required cache warmers are *always* executed when the Kernel boots for the first time;
* Optional cache warmers are *only* executed from the CLI via cache:warmup
These new rules means that all the configuration settings for the cache
warmers have been removed. So, if you want the best performance, remember to
warmup the cache when going to production.
This also fixed quite a few bugs.
Cache warmer will come in the next commits.
To warm up the cache on a production server, you can use
the cache:warmup command:
./app/console_prod cache:warmup
