band-aid to avoid figure collision

The figure counter is not global, so a cell with multiple outputs,
followed by another cell with outputs will result in clobbered figures.

This is a band-aid fix to avoid collisions on cells with less than 100 figures,
until the proper state is handled.

converters/transformers.py

@@ -44,7 +44,7 b' class ConfigurableTransformers(GlobalConfigurable):'
         try :
             for worksheet in nb.worksheets :
                 for index, cell in enumerate(worksheet.cells):
-                    worksheet.cells[index], other = self.cell_transform(cell, other, index)
+                    worksheet.cells[index], other = self.cell_transform(cell, other, 100*index)
             return nb, other
         except NotImplementedError:
             raise NotImplementedError('should be implemented by subclass')