CVS commit by blackie: 

* Display a grey thumbnail when the image for one reason or the
other couldn't be loaded. Previously this resulted in the
thumbnail containing garbage pixels. 
Thanks to Robert L Krawitz <rlk@alum.mit.edu>


  M +7 -0      ChangeLog   1.154
  M +2 -2      displayarea.cpp   1.34
  M +1 -1      displayarea.h   1.26
  M +3 -1      export.cpp   1.26
  M +15 -15    export.h   1.14
  M +3 -3      htmlexportdialog.cpp   1.52
  M +1 -1      htmlexportdialog.h   1.21
  M +1 -1      iconviewtooltip.cpp   1.14
  M +1 -1      iconviewtooltip.h   1.9
  M +1 -1      imageclient.h   1.8
  M +47 -39    imageloader.cpp   1.30
  M +12 -2     imagemanager.cpp   1.26
  M +3 -0      imagemanager.h   1.14
  M +5 -4      imagepreview.cpp   1.21
  M +2 -2      imagepreview.h   1.14
  M +5 -3      thumbnail.cpp   1.40
  M +1 -1      thumbnail.h   1.17
  M +1 -1      thumbnailbuilder.cpp   1.6
  M +1 -1      thumbnailbuilder.h   1.5