getSizeFromImageDisplay method was returning (heigh, width), but all other
 methods were returning (widht height). In addition to this, there was
 mistakes :
from Document/Image.py +295 :
                        'width': self.getSizeFromImageDisplay(id)[0],
                        'height': self.getSizeFromImageDisplay(id)[1],
and also l 450:
      (width, height) = self.getSizeFromImageDisplay(display)

the use of width and height was mixed up.
Currently, all default preferences display size define squares (width = heigh),
 so this mistake was never detected.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@31531 20353a03-c40f-0410-a6d1-a30d3c3de9de