byobu 5.18

- add dep on coreutils to get GNU readlink
 - simplify caveats

Closes Homebrew/homebrew#11160.
Closes Homebrew/homebrew#12006.

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

Formula/byobu.rb

@@ -1,9 +1,11 @@
 require 'formula'
 
 class Byobu < Formula
-  url 'http://launchpad.net/byobu/trunk/5.12/+download/byobu_5.12.orig.tar.gz'
   homepage 'http://launchpad.net/byobu'
-  md5 '15c3d0fd2923fba0a6d77fc52d59b81a'
+  url 'http://launchpad.net/byobu/trunk/5.18/+download/byobu_5.18.orig.tar.gz'
+  md5 '5940cef1ae3d750b5712793a90901d67'
+
+  depends_on 'coreutils'
 
   def install
     system "./configure", "--prefix=#{prefix}"
@@ -11,8 +13,8 @@ class Byobu < Formula
   end
 
   def caveats; <<-EOS.undent
-    After installing, add the following path to your .bashrc or .zshrc file:
-      export BYOBU_PREFIX=`brew --prefix`
+    Add the following to your shell configuration file:
+      export BYOBU_PREFIX=$(brew --prefix)
     EOS
   end
 end