New string as part 'Keep progress dialog open longer', b=133825, r=akkana, sr=kin, a=asa, adt1.0.0+

editor/ui/dialogs/locale/en-US/EditorPublishProgress.dtd

@@ -26,6 +26,7 @@
 <!ENTITY docSubdir.label       "Page subdirectory:">
 <!ENTITY otherSubdir.label     "Image subdirectory:">
 
+<!ENTITY status.label          "Publishing...">
 <!ENTITY fileList.label        "Publishing Status">
 <!ENTITY statusHeader.label    "Status">
 <!ENTITY filenameHeader.label  "Filename">