Feature: AOP

This pull request adds AOP possibilities to injection:

```php
$inject->bind('inject.unittest.fixture.Storage', new ProxyProvider(
  'inject.unittest.fixture.FileSystem',
  $inject,
  newinstance('inject.MethodInterception', [], [
    'invoke' => function($invocation) use($log) {
      $log[]= $invocation;
      return $invocation->proceed();
    }
  ])
));
```

The log contains `inject.MethodInvocation` instances after the invocation.