updated build elevation mosaic tools and raster functions

2 new tools added to manage elevation data and create source/derived
elevation mosaic datasets.  New Raster functions were added and older
raster functions were updated.
Updates to tool in tool box

doucmentation changes and tool fixes for all tools
more fixes for missing stuff

matt
Merge pull request #72 from NatalieCampos/master

updated build elevation mosaic tools and raster functions