Pull up `VCS.short_revision` from `VCS::SVN`

tool/lib/vcs.rb

@@ -104,6 +104,10 @@ class VCS
     ]
   end
 
+  def self.short_revision(rev)
+    rev
+  end
+
   attr_reader :srcdir
 
   def initialize(path)
@@ -251,10 +255,6 @@ class VCS
       "r#{rev}"
     end
 
-    def self.short_revision(rev)
-      rev
-    end
-
     def _get_revisions(path, srcdir = nil)
       if srcdir and self.class.local_path?(path)
         path = File.join(srcdir, path)