CVSDownloadStrategy: correctly stage all files

The FileUtils.cp_r function with a wildcard doesn't copy hidden files
(starting with a dot) Instead of copying everything selected by *,
select all the folder content.

See: http://www.ruby-doc.org/core-1.9.3/Dir.html#method-c-glob

Closes Homebrew/homebrew#8873.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Library/Homebrew/download_strategy.rb

@@ -416,7 +416,7 @@ class CVSDownloadStrategy < AbstractDownloadStrategy
   end
 
   def stage
-    FileUtils.cp_r Dir[@co+"*"], Dir.pwd
+    FileUtils.cp_r Dir[@co+"{.}"], Dir.pwd
 
     require 'find'
     Find.find(Dir.pwd) do |path|