fpspreadsheet:
- test for bug 26447: fpspreadsheet columns >26 wrong with ooxml (patch) as fixed in r3273
- fix typo in documentation rfRow=>rfRelRow
- cosmetic changes



git-svn-id: http://svn.code.sf.net/p/lazarus-ccr/svn@3276 8e941d3f-bd1b-0410-a28a-d453659cc2b4