ref #135 Navigation/history

* Adds a history for cgsee navigation. 
* Supports all implemented manipulators and static presets. 
* Adds a gui widget to visualize all saved steps with a small thumbnail.
please provide alt key accelerators by placing an ```&``` in front of the intended access character (see http://doc.qt.digia.com/qt-maemo/linguist-translators.html#alt-key-accelerators for more)