localrepo: make it possible to pass multiple path elements to join and wjoin

This makes join and wjoin behave in the same way as os.path.join. That is, it
makes it possible to pass more than one path element to them.

Note that the first path element is still required, as it was before this patch,
and as is the case for os.path.join.

mercurial/localrepo.py

@@ -739,11 +739,11 b' class localrepository(object):'
         # if publishing we can't copy if there is filtered content
         return not self.filtered('visible').changelog.filteredrevs
 
-    def join(self, f):
-        return os.path.join(self.path, f)
+    def join(self, f, *insidef):
+        return os.path.join(self.path, f, *insidef)
 
-    def wjoin(self, f):
-        return os.path.join(self.root, f)
+    def wjoin(self, f, *insidef):
+        return os.path.join(self.root, f, *insidef)
 
     def file(self, f):
         if f[0] == '/':