Fix rabbitmq formula

* store RabbitMQ Erlang binaries in lib/rabbitmq/erlang/lib to avoid overwriting of lib/erlang/lib
* add HOMEBREW_PREFIX in RabbitMQ scripts

Formula/rabbitmq.rb

@@ -1,21 +1,32 @@
 require 'brewkit'
 
 class Rabbitmq <Formula
-  @homepage='http://rabbitmq.com'
-  @url='http://www.rabbitmq.com/releases/rabbitmq-server/v1.6.0/rabbitmq-server-1.6.0.tar.gz'
-  @md5='af3b0d868d58e5aefb4f0837b82ca010'
+  homepage 'http://rabbitmq.com'
+  url 'http://www.rabbitmq.com/releases/rabbitmq-server/v1.6.0/rabbitmq-server-1.6.0.tar.gz'
+  md5 'af3b0d868d58e5aefb4f0837b82ca010'
 
   depends_on 'erlang'
 
-  def erlang_libdir
-    prefix + "lib" + "erlang" + "lib"
-  end
-
   def install
+    erlang_libdir = lib + "rabbitmq" + "erlang" + "lib"
+    target_dir = "#{erlang_libdir}/rabbitmq-#{version}"
     system "make"
-    system "TARGET_DIR=#{erlang_libdir}/rabbitmq-#{version} \
+    system "TARGET_DIR=#{target_dir} \
                 MAN_DIR=#{man} \
                 SBIN_DIR=#{sbin} \
                 make install"
+
+    (etc + "rabbitmq").mkpath
+    (var + "lib" + "rabbitmq").mkpath
+    (var + "log" + "couchdb").mkpath
+
+    %w{rabbitmq-server rabbitmq-multi rabbitmqctl}.each do |script|
+      inreplace sbin+script, '/etc/rabbitmq', "#{etc}/rabbitmq"
+      inreplace sbin+script, '/var/log/rabbitmq', "#{var}/log/rabbitmq"
+      inreplace sbin+script, '/var/lib/rabbitmq', "#{var}/lib/rabbitmq"
+      # RabbitMQ Erlang binaries are installed in lib/rabbitmq/erlang/lib/rabbitmq-x.y.z/ebin
+      # therefore need to add this path for erl -pa
+      inreplace sbin+script, '`dirname $0`/..', "#{target_dir}"
+    end
   end
 end