anchor.diff:  
   set Action=
   if "%~1" == "get"       set Action=get
  +if "%~1" == "update"    set Action=update
   if "%~1" == "help"      set Action=help
   if "%~1" == ""          set Action=help
   
  
positive.code: echo Usage: %Script% [ACTION]
  echo where ACTION is:
  echo   get       -- download and unpack GDAL libraries and C# bindings
  echo   help      -- display this message (default)
  
  goto :eof
  
negative.code: set ProjectUrl=http://landis-spatial.googlecode.com/
  set PackageList=gdal-%GdalVersion%-csharp.txt
  if not exist %PackageList% set GetPackageList=yes
  if "%Action%" == "update" set GetPackageList=yes
  if "%GetPackageList%" == "yes" call :getPkgList
  
  rem  Determine the platform (win32 or win64)
  