[TASK] New FCE Thumbnail

New Content Element ThumbnailBox.html. Uses FAL for Images. The fist Image is used as Thumbnail, the others are shown in a Modal Box.

![bildschirmfoto 2014-10-02 um 13 57 47](https://cloud.githubusercontent.com/assets/6050140/4490435/6e101962-4a2b-11e4-89b4-c81c655ab31f.png)
![bildschirmfoto 2014-10-02 um 13 58 02](https://cloud.githubusercontent.com/assets/6050140/4490437/74dc9432-4a2b-11e4-979c-29e2d91cc7e8.png)