0.0.1:
- 22/01/2015:
   - try to retrieve cell's styles, number formatings, formula with Index and comments in .sdc files,
   - try to retrieve basic shapes and bitmap in .sda files + some formatting(but not all),
   - try to retrieve the bitmap in .sdg files,
   - add a new kind in STOFFDocument.hxx: STOFF_K_GRAPHIC to indicate that the file is a .sdg file,

   + finish to implement the StarItemPool and add functions to retrieve many
     attributes' contents,
   + update many styles classes to store only needed data,
   + correct a problem when we fail to retrieve all the texts in small EditZone
     (still with no formattings)
   + add a convertissor to create .svg files
   + correct some bugs found by afl
   
0.0.0:
- 09/29/2015: begin to reconstruct the "basic" content of sdc files, ie.
   - the sheets' names
   - the value, text or formula(if they do not contain any Index) which appear in sheet's cells
   - the column and row widths
   but not:
   - numbers' formating
   - cells' formating
   - notes, fields, embedding objects, ...
