Including a db wrapper function that will format PDO params for you

## PDO helper

I'm adding a function that makes it a bit easier to generate PDO parameters. 

**From this**

	$params = array(
				'candy' => array('value' => $this->favoriteCandy, 'pdoType' => PDO::PARAM_STR),
				'person' => array('value' => $this->person, 'pdoType' => PDO::PARAM_INT)
			);
	$this->db->insert($sql, $params);
	
**To this**

	$values = array(
			'candy' => $this->favoriteCandy,
			'person' => $this->person
		);
	$params = $this->db->generate_params($values);
	$this->db->insert($sql, $params);

Pass this function an array of keys and values that you want to use in your DB query. `generate_params()` will return you a valid PDO array to use with your INSERT and UPDATE statements.

Supported types:
=================
	PARAM_BOOL
	PARAM_NULL
	PARAM_INT
	PARAM_STR

Unsupported types:
=================
	PARAM_LOB
	PARAM_INPUT_OUTPUT
	PARAM_STMT (No drivers support this anyways)

**Note:**

If you need to use one of these unsupported types, you'll have to generate the params by hand.

Full Example:
========

	$sql = <<<SQL
		INSERT INTO Days (Day, DayNumber, isHoliday)
		VALUES (:day, :dayNumber, :isHoliday);
	SQL;
	
	$values = array(
		'day' => 'tuesday', 
		'dayNumber' => 2, 
		'isHoliday' => true
	);
	$params = $this->db->generate_params($values);
	$this->db->insert($sql, $params);