so that save/save as works correctly for non-8859-1 string. rename ImageDocument.properties to MediaDocument.properties and move to content/html/document/src. (r=cbiesinger for an earlier patch, sr=bzbarsky) git-svn-id: svn://10.0.0.236/trunk@141073 18797224-902f-48f8-a5cc-f745e15eee43