* New model syntax:

package M::T;
use ORM;
extends 'ORM::Model';
sub _db_table { 'table_name' }
has_field 'id'	=> ( isa => 'Int' );

Not required in attribute description anymore:
- metaclass => 'ORM::Meta::Attribute',
- is => 'rw'

And a somewhat faster work because of that. Credit goes to https://github.com/kainwinterheart

* Minor "exists" fixes.