Log Message:
Update to 0.70

Upstream changes:
0.70	- 02 Mar 2017, H.Merijn Brand
    * Add label functionality to ::Sheet
    * Add ->column and ->cellcolumn for ::Sheet
    * Add col2label sub/method
    * Sanitize xls2csv export filenames
    * Fix sorting in xlscat for un-aligned columns
    * It's 2017
    * Be overly verbose about maxrow and maxcol being 1-based (RT#120476)