title: Sequelize error when using "where" and "in" on a subarray
body: <p>This is my model definition:</p>
  
  <pre><code>var Tag = sequelize.define('Tag', {
      name: Sequelize.STRING
  });
  
  var Event = sequelize.define('Event', {
      name: Sequelize.STRING,
  });
  
  Event.hasMany(Tag, {as: 'tags', through: 'event_tags', foreignKey: 'eventId'});
  Tag.hasMany(Event, {as: 'events', through: 'event_tags', foreignKey: 'tagId'});
  </code></pre>
  
  <p>In words this is: there are events and tags. Events are tagged with many tags.</p>
  
  <p>I'm trying to run this query:</p>
  
  <pre><code>Event
  .findAndCountAll({
      include: [{model: Tag, as: 'tags'}],
      where: {'tags.id': {in: [1,2,3,4]}},
      order: order,
      limit: pageSize,
      offset: pageSize * (page - 1),
  })
  .success(function(result) {
  
      ...
  });
  </code></pre>
  
  <p>But I'm getting this error:</p>
  
  <pre><code>   \node_modules\sequelize\lib\dialects\abstract\query-generator.js:1134
            var logicResult = Utils.getWhereLogic(logic, hash[key][logic]);
                                                                  ^
     TypeError: Cannot read property 'in' of undefined
  </code></pre>
  
  <p>What am I doing wrong?</p>
  
  <p>I've used before the "in" expression, for example here:</p>
  
  <pre><code> Tag
   .find({
        where: {id: {in: [1,2,3,4]}}
   }).success(...)
  </code></pre>
  
  <p>And it worked just fine.<br></p>
  
  <p>I've never used the in expression with a sub-array though, as in this case. So I don't know if thats the correct way to do it.</p>