WIP: Fix saving of coordinate class objects in *.ita files

Fix saving of coordinate class objects. itaCoordinates are currently stored as MATLAB class objects when saving *.ita files. Use the saveobj method of itaCoordinates when writing .ita files to save the itaCoordinates as a struct, not requiring ITA-Toolbox functionality to open the files.

This change will result in a break with the backwards compatibility.

Reading *.ita files generated with newer versions on a version prior tp this will result in a loss of:

• channelCoordinates
• objectCoordinates
• objectViewVector
• objectUpVector

All other data will remain intact.

Todo:

• Cleanup saveobj for itaAudio
• Cleanup saveobj for itaSuper
• Cleanup saveobj for itaCoordinates
• Cleanup ita_write_ita