Retired "grep" formula.

Grep comes with OS X, so we're moving it to the duplicates branch:
http://github.com/adamv/homebrew/tree/duplicates

Formula/grep.rb

@@ -1,27 +0,0 @@
-require 'formula'
-
-class Grep <Formula
-  homepage 'http://www.gnu.org/software/grep/'
-  url 'http://mirror.its.uidaho.edu/pub/gnu/grep/grep-2.5.4.tar.bz2'
-  md5 '5650ee2ae6ea4b39e9459d7d0585b315'
-
-  depends_on 'gettext'
-  depends_on 'pcre'
-
-  def install
-    system "./configure", "--disable-debug",
-                          "--disable-dependency-tracking",
-                          "--disable-nls",
-                          "--prefix=#{prefix}",
-                          "--infodir=#{info}",
-                          "--mandir=#{man}"
-
-    # Configure gives me 2 copies of -lpcre and no -lintl, so fix that
-    inreplace "src/Makefile" do |s|
-      s.change_make_var! "LIBS", "-lintl -lpcre"
-    end
-
-    system "make"
-    system "make install"
-  end
-end