1. First cut of a Special System Directory replacement (nsDirectoryService).

It is a nsIProperty.

2. Updates to the nsIFile and nsILocalFile interfaces based on conversations
   with warren. (thanks)

3. Updated windows mac and unix implementations based on interface changes.
   Mac and windows changes need to be reviewed.


                          Not part of build.

xpcom/io/nsLocalFileUnix.cpp

@@ -86,24 +86,31 @@ nsLocalFile::Create(nsISupports *outer, const nsIID &aIID, void **aInstancePtr)
     return inst->QueryInterface(aIID, aInstancePtr);
 }
 
-NS_IMETHODIMP
-nsLocalFile::InitWithKey(const char *fileKey)
-{
-    return NS_ERROR_NOT_IMPLEMENTED;
-}
 
 NS_IMETHODIMP
-nsLocalFile::InitWithFile(nsIFile *file)
+nsLocalFile::Clone(nsIFile **file)
 {
     NS_ENSURE_ARG(file);
     
-    invalidateCache();
-    if (NS_FAILED(file->GetPath(nsIFile::NATIVE_PATH, getter_Copies(mPath))))
-        return NS_ERROR_FAILURE;
-    
-    if ((const char *)mPath == 0)
-        return NS_ERROR_FILE_UNRECOGNIZED_PATH;
+    *file = nsnull;
 
+    nsCOMPtr<nsILocalFile> localFile;
+    nsresult rv = nsComponentManager::CreateInstance(NS_LOCAL_FILE_PROGID, 
+                                                     nsnull, 
+                                                     nsCOMTypeInfo<nsILocalFile>::GetIID(), 
+                                                     getter_AddRefs(localFile));
+    
+    if (NS_FAILED(rv)) 
+        return rv;
+    
+    rv = localfile->InitWithPath(mPath);
+    
+    if (NS_FAILED(rv)) 
+        return rv;
+
+    *file = localFile;
+    NS_ADDREF(*file);
+    
     return NS_OK;
 }
 
@@ -127,6 +134,22 @@ nsLocalFile::createAllParentDirectories(PRUint32 permissions)
     return NS_ERROR_NOT_IMPLEMENTED;
 }
 
+
+NS_IMETHODIMP  
+nsLocalFile::Open(PRInt32 flags, PRInt32 mode, PRFileDesc **_retval)
+{
+    CHECK_mPath();
+   
+    *_retval = PR_Open(mPath, flags, mode);
+    
+    if (*_retval)
+        return NS_OK;
+
+    return NS_ERROR_FAILURE;
+}
+
+
+
 NS_IMETHODIMP
 nsLocalFile::Create(PRUint32 type, PRUint32 permissions)
 {