Refactored PropertyVisualization plugin.
The code was written by Max Lyon. New features are: - Changed plugin's architecture so that it can now be extended to support generic object types (implementation for OpenVolumeMesh has been added). - Read/write properties from/into files. Also reading props into existing properties is now supported. - Multiple properties can be selected (multiple toolboxes appear) and combined. - Documentation has been added. git-svn-id: http://www.openflipper.org/svnrepo/OpenFlipper/branches/Free@15818 383ad7c9-94d9-4d36-a494-682f7c89f535