Added a templated *Model and *ModelManager generator script
Added missing BlackBoard files
*Model::fromJson and *ModelManager::from{Single}Json refactoring:

- moved OgreModelManager::fromJson(Json::Value &models to _ModelManager::fromJson(Json::Value &models) so that every _ModelManager specialization can benefit of it.
- implemented _ModelManager::fromSingleJson(Json::Value &model), which is the single model version of fromJson, called by fromJson fr each model serialization.
- downside of refacto is that any Model subclass instances can be called the fromJson(Json::Value &value) method they inherit from Model, though this is not likely, as common usage is made through a ModelManager, which knows how which *Model::fromJson to call.
- added OgreModel::fromJson(Json::Value &value), always returning false, as this is not the right deserialization method to call.