Save and Open map data

I've now implemented a save and open functionality. This enables us to save the raw data (positions, headings, distance etc.) as a XML file that we later on can open and import into the application.
This is a useful function in many ways. We can now work on the server functionality even though we don't have the NXT with us (for example when we are in school). We just use saved data and let the serverapp process this instead of data retrieved by Bluetooth. As it is for now all the data is imported at once but I will implement a emulating functionality. This will add the saved data with the same time delays as it was recorded. This will enable us to play back what happened. I think I will implement this by adding one more connection type. Instead of choosing between USB and Bluetooth you will be given the choice File and instead of passing the name of the NXT you pass a filepath to the file containing raw values.

One of our goals is also to publish the data to a webserver so that a client can connect and see the map being created in real time. The export function is one step towards that.

This is how the new control panel looks like: