Support prepared statements

[mbabker]

Now that the database API consistently uses (and requires) prepared statement support, this package should support that as well. To do a lookup by anything that's not a PK still requires manual quoting of all values.

// Current behavior
$data = (new MyModel)->where('name = ' . $db->quote($name))->get();

// Preferred behavior
$data = (new MyModel)->where('name', '=', $name);

// With this method prototype in the Query class
public function where(string $column, $value, string $operator = '=', string $glue = 'AND')
{
    $paramName = ':' . $column;

    $this->query->where($column . ' ' . $operator . ' ' . $paramName, $glue);

    // TODO - Support defining the parameter type too, or at least detecting based on the $value param type?
    $this->query->bind($paramName, $value);

    return $this;
}

[wilsonge]

Closing for the PR in #20