Change the scenepicker filter so that the 2D view can only pick nodes that are visible and appropriate for that mode.  Put gaurds around the mouse press and release events to stop unwanted behaviour when pressing two buttons at once.
Fixing serialization bug where the curves were not creating recreated properly.  Changed the handling of updates to the plane so that it doesn't reset the view all the time, it still jumpms a little when the 2D view is off plane centre. Tidy up picking filter.
Fixing bug where zero length curves were being maintained by the model instead of deleting them.
Use information gathered from dicom images to scale the texture to the correct size.
Merge pull request #2 from hsorby/master

Use information available from DICOM images and Bug Fixes