Fix paranoid clause treating all arrays as if they contained only strings

Basically, paranoidClause in model.js was treating all arrays as arrays of strings.

Insert the following snippet at line 2102 of dao-factory.test.js and run `make {any-db}` to see the issue. IndexOf was being called on arbitrary objects.

```javascript
    it.only('should not fail when array contains Sequelize.or / and', function (done) {
      this.User.findAll({
        where: [
          this.sequelize.or({ username: 'vader' }, { username: 'luke' }),
          this.sequelize.and({ id: [1, 2, 3] })
        ]
      })
        .then(function(res) {
          expect(res).to.have.length(2)
          done()
        })
        .catch(function(e) { done(e) })
    })
```