This allows for better conventions and better error messages if you
use the wrong configuration alias in a config file.
This is also the first step for a bigger refactoring of how the configuration
works (see next commits).
* Bundle::registerExtensions() method has been renamed to Bundle::build()
* The "main" DIC extension must be renamed to the new convention to be
automatically registered:
SensioBlogBundle -> DependencyInjection\SensioBlogExtension
* The main DIC extension alias must follow the convention:
sensio_blog for SensioBlogBundle
* If you have more than one extension for a bundle (which should really
never be the case), they must be registered manually by overriding the
build() method
* If you use YAML or PHP for your configuration, renamed the following
configuration entry points in your configs:
app -> framework
webprofiler -> web_profiler
doctrine_odm -> doctrine_mongo_db
