Use INI entries to control ORM options

ie,

```
[phalcon]
extension = phalcon.so
phalcon.orm.events = On
phalcon.orm.virtual_foreign_keys = On
phalcon.orm.column_renaming = On
phalcon.orm.not_null_validations = On
phalcon.orm.exception_on_failed_save = Off
phalcon.orm.enable_literals = On
```