Create or update

When working with a server there are models which are updated. The purpose of this pull request is to automate the creating and updating of models. This is done with several annotations. First there is a new method on the table annotation where you specify the unique identifier of a model. Based on this the update method will choose if a model entity is already present in the database. Furthermore are there some column annotations with wich you specify what update action should be chosen. The following can be chosen NO_ACTION, REPLACE, UPDATE wherefrom UPDATE only makes sense when the column is a foreign key.