Changes in Version 0.1-5

  o  Import sp and rgeos package functions in the NAMESPACE file.

Changes in Version 0.1-4

  o  Removed DEM data set and Example 3 from documentation.

  o  Replaced deprecated sp::overlay function with sp::over.

Changes in Version 0.1-2

  o  Added option to crop spatial domain using polygons.

Changes in Version 0.1-1

  o  Sorted z levels to make color specification much easier when plotting.

  o  Added option to limit raster extent in the four coordinate directions.

  o  Fixed error with list construction; error sometimes occurs when specifying
     breakpoints.

  o  Updated examples in documentation
