Updated CxImage README

src/3rdParty/CxImage/README

@@ -1,9 +1,13 @@
-Yanked from FreeCAD forum post by wmayer 17 July 2014
+Yanked from FreeCAD forum posts by wmayer 17 July and 22 August 2014
 http://forum.freecadweb.org/viewtopic.php?f=10&t=7054
+http://forum.freecadweb.org/viewtopic.php?f=17&t=7432
 
 The CxImage is only used for a Windows thumbnailer. The utility
 "ThumbnailProvider" is a DLL which can be registered to Windows as a so called
 shell extension.  This utility is able to create a preview image of an FCStd
 project file and CxImage is needed to convert the data into a format that
 Windows expects.
 
+The format Windows accepts is a BITMAP handle for which Qt could also be used.
+But this requires a dependency of two rather heavy DLLs (QtCore, QtGui) and
+with a statically linked CxImage we don't have this problem.