Generate Mysql model function, if you are a model first, you can generate the table based on it.
Usage: ModelName = sailor.model("model_name")
	ModelName:generate_mysql()
Modified model validate to use valua properly.

It will now validate attributes in the correct order and validation functions may be reused. It is necessary to rewrite generate mysql function and update the model examples.
Commenting generate mysql function for the moment
Fixing stuff to be compatible with new model changes
Merge branch 'master' of https://github.com/Etiene/sailor