util: simplify unique

util: simplify unique

--- a/mercurial/util.py	Thu Dec 27 23:55:40 2007 -0600
+++ b/mercurial/util.py	Thu Dec 27 23:55:40 2007 -0600
@@ -224,13 +224,7 @@
 
 def unique(g):
     """return the uniq elements of iterable g"""
-    seen = {}
-    l = []
-    for f in g:
-        if f not in seen:
-            seen[f] = 1
-            l.append(f)
-    return l
+    return dict.fromkeys(g).keys()
 
 class Abort(Exception):
     """Raised if a command needs to print an error and exit."""