Mapping import

This PR aims to:
- generate the *Metadata files which describe the entity class* from an Existing Database (`php app/console doctrine:mapping:import --force InnovareMainBundle yml`).
- generate the  *entity classes* from the previous *Metadata files*

Issues:
- For the ENUM type (not supported by DBAL by default).
I changed the file `app/config/config.yml`
 adding 
`mapping_types:
                    enum: string`

- For missing `primary key` `alter table anagrafica add column `id` int(10) unsigned primary KEY AUTO_INCREMENT;`

Reference:
http://symfony.com/doc/current/cookbook/doctrine/reverse_engineering.html