Changes in version 0.0.1                        

  - New 'nasadem()' for the OpenTopo VRT.

  - dsn now contains the source functions that whatarelief had,
    whatarelief imports them and re-exports some.

  - New functions for 'datatype()' .

  - New mem() function to reference an in memory array.

  - New functions sds() and vrtcon().

  - First basic functions.