Not all "strict" params should be "Requirements" in the documentation, closes #229

If you want to have "strict" QueryParams (for Regex checking for example) with the "nullable=true" option, this FOSRestBundle annotation should still be considered a Filter in the documentation and not a Requirement:
```
@Rest\QueryParam(name="types", requirements="^([a-z_]+,{0,1})+$", strict=true, nullable=true, description="Example"
```

The _types_ QueryParam should still be considered a **Filter** even if we use the "strict=true" annotation, because we are using it just to ensure that the Regex check throws a "400 Bad Request" response when it is necessary.