updated copyright in source comments

src/com/t_oster/liblasercut/BlackWhiteRaster.java

...er/liblasercut/FloatPowerSpeedFocusFrequencyProperty.java

src/com/t_oster/liblasercut/GreyscaleRaster.java

src/com/t_oster/liblasercut/IllegalJobException.java

src/com/t_oster/liblasercut/LaserCutter.java

src/com/t_oster/liblasercut/LaserJob.java

src/com/t_oster/liblasercut/LaserProperty.java

src/com/t_oster/liblasercut/LibInfo.java

...t_oster/liblasercut/PowerSpeedFocusFrequencyProperty.java

src/com/t_oster/liblasercut/PowerSpeedFocusProperty.java

src/com/t_oster/liblasercut/ProgressListener.java

src/com/t_oster/liblasercut/Raster3dPart.java

src/com/t_oster/liblasercut/RasterPart.java

src/com/t_oster/liblasercut/TimeIntensiveOperation.java

src/com/t_oster/liblasercut/VectorCommand.java

src/com/t_oster/liblasercut/VectorPart.java

src/com/t_oster/liblasercut/dithering/Average.java

...com/t_oster/liblasercut/dithering/DitheringAlgorithm.java

src/com/t_oster/liblasercut/dithering/FloydSteinberg.java

src/com/t_oster/liblasercut/dithering/Grid.java