Update: added 'dplyr' to list of dependencies.
Initial upload: function `gsodColWidth()` that returns fixed column widths of GSOD ASCII data.
Major update: added documentation to `dlGsodStations()`, implemented `dplyr` filtering and changed variable names.
Major update: added documentation to `gzGsodStations()`, facilitated concatenation procedure, excluded obsolete arguments and changed variable names.