Now that we have a compilation phase for the DIC, using tags after compilation
is not needed anymore.
Tags were introduced to allow several independant bundles to be able to
interact which each others (remember that each extension knows nothing about
the others).
But during the compilation phase, the container has been merged ans so, all
the information from all bundles are available. This is then the right place
to deal with tags. That way, less work is needed at runtime and the DIC class
in the cache is also much smaller.
For simple cases, it means that you need to process the tag in a compiler pass
and store the information you need in a DIC parameter (have a look at the
TranslatorPass for a very simple example).
So, the PHP dumper does not add tags to the dumped PHP class anymore (it does
not implements TaggedContainerInterface anymore). But tags are still available
on ContainerBuilder instances.
* removed the __call() method in Container: it means that now, there is only
one way to get a service: via the get() method;
* removed the $shared variable in the dumped Container classes (we now use
the $services variable from the parent class directly -- this is where we
have a performance improvement);
* optimized the PHP Dumper output.
In the dumped PHP class, we must use get() and not get*Service() methods to get services.
That's because all calls must be managed by get(). From the outside, you can call
get*Service() because as they are protected, they are caught by the __call() method;
which is not the case obviously when it is used internally.
If not, if you override a service with set(), this won't work when a service
depends on this one (the default one will still be used).
