* 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).
