making ODF validator happy. Excel 2010 still chokes upon this...
unified lib version - ugly and dirty
XLSX: dumbing xfid
XLSX redundancy collapsing: more memory - less voodoo
Demo: XLSX works.... more or less
little chained-id optimization
Example: Convert formulas in example. Added checks for delphi <= XE2 and zip.

R1C1 notation is better (simplest) for conversion.