bug 157624 - prep for freezing nsISupports* primitives by renaming the string classes appropriately

nsISupportsString  -> nsISupportsCString
nsISupportsWString -> nsISupportsString
r=dougt, sr=jag

suite/common/contentAreaUtils.js

@@ -420,7 +420,7 @@ nsHeaderSniffer.prototype = {
             try {
               this.contentEncodingType =
                 encodingEnumerator.getNext().
-                  QueryInterface(Components.interfaces.nsISupportsString).data;
+                  QueryInterface(Components.interfaces.nsISupportsCString).data;
             } catch (e) {
             }
           }

suite/common/openLocation.js

@@ -75,7 +75,7 @@ function onLoad()
       if (element)
         dialog.openAppList.selectedItem = element;
       dialog.input.value = pref.getComplexValue("general.open_location.last_url",
-                                                Components.interfaces.nsISupportsWString).data;
+                                                Components.interfaces.nsISupportsString).data;
     }
     catch(ex) {
     }
@@ -125,11 +125,11 @@ function open()
   }
 
   if (pref) {
-    var str = Components.classes["@mozilla.org/supports-wstring;1"]
+    var str = Components.classes["@mozilla.org/supports-string;1"]
-                        .createInstance(Components.interfaces.nsISupportsWString);
+                        .createInstance(Components.interfaces.nsISupportsString);
     str.data = dialog.input.value;
     pref.setComplexValue("general.open_location.last_url",
-                         Components.interfaces.nsISupportsWString, str);
+                         Components.interfaces.nsISupportsString, str);
     pref.setIntPref("general.open_location.last_window_choice", dialog.openAppList.value);
   }