public / sequelize

fixes a TypeError that occurs if a 'rawSelect' query does not return a row (data is null).

I discovered the problem trying perform a `Model.count()` in combination with a `group` option on a MySQL database,MySQL does not return a record for query such as this:

```sql
SELECT 
    count(*) AS `count` 
FROM 
    `SomeTable` 
WHERE 
    `category_id` = 1
GROUP BY 
    `my_grouping_field`
```

In Sequelize the previous query would be done like so:

```js
SomeTable.count({
  group: 'my_grouping_field',
  where: {
    category_id: 1
  }
});
```

assuming the `category_id` WHERE clause returns zero records you end up with the following TypeError:

```bash
TypeError: Cannot read property 'count' of null
    at null.<anonymous> (some-project/node_modules/sequelize/lib/query-interface.js:314:28)
    at EventEmitter.emit (events.js:117:20)
    at null.<anonymous> (some-project/node_modules/sequelize/lib/dialects/mysql/query.js:32:14)
    at Query.Sequence.end (some-project/node_modules/mysql/lib/protocol/sequences/Sequence.js:66:24)
    at Query._handleFinalResultPacket (some-project/node_modules/mysql/lib/protocol/sequences/Query.js:139:8)
    at Query.EofPacket (some-project/node_modules/mysql/lib/protocol/sequences/Query.js:123:8)
    at Protocol._parsePacket (some-project/node_modules/mysql/lib/protocol/Protocol.js:169:24)
    at Parser.write (some-project/node_modules/mysql/lib/protocol/Parser.js:62:12)
    at Protocol.write (some-project/node_modules/mysql/lib/protocol/Protocol.js:36:16)
    at write (_stream_readable.js:557:24)
```

fix the bug `findAndCountAll` not working on postgresql.

Fix (global) db leakage, by making db local.

Thanks to mickhansen for the fix.

copy `where` array, avoid changed by internal.

DAOFactory.update() will now skip validations for columns that we're not...

tests & bugfixes for DAO-Factory.update and array of values in where clause

postgres requires empty array to be explicitly cast on update

Add support for typed arrays in SqlString.escape and SqlString.arrayToList

Cleaned up the postgres connector-manager/query code, updated node-postg...

…ndency, and made sure pg.Client ended correctly on drain to prevent leaks for non pooling connections.

Properly copy the options objects passed to find and findall

Fixes a bug with .destroy() on a DAO record