removes binary? hack for RDoc, API requires RDoc 3 and horo 1.0.3

Rakefile

@@ -1,5 +1,5 @@
 #!/usr/bin/env rake
-gem 'rdoc', '>= 2.5.10'
+gem 'rdoc', '~> 3.0'
 require 'rdoc'
 
 require 'rdoc/task'
@@ -14,31 +14,6 @@ task :build => "all:build"
 desc "Release all gems to gemcutter and create a tag"
 task :release => "all:release"
 
-# RDoc skips some files in the Rails tree due to its binary? predicate. This is a quick
-# hack for edge docs, until we decide which is the correct way to address this issue.
-# If not fixed in RDoc itself, via an option or something, we should probably move this
-# to railties and use it also in doc:rails.
-def hijack_rdoc!
-  require "rdoc/parser"
-  class << RDoc::Parser
-    def binary?(file)
-      s = File.read(file, 1024) or return false
-
-      if s[0, 2] == Marshal.dump('')[0, 2] then
-        true
-      elsif file =~ /erb\.rb$/ then
-        false
-      elsif s.index("\x00") then # ORIGINAL is s.scan(/<%|%>/).length >= 4 || s.index("\x00")
-        true
-      elsif 0.respond_to? :fdiv then
-        s.count("^ -~\t\r\n").fdiv(s.size) > 0.3
-      else # HACK 1.8.6
-        (s.count("^ -~\t\r\n").to_f / s.size) > 0.3
-      end
-    end
-  end
-end
-
 PROJECTS = %w(activesupport activemodel actionpack actionmailer activeresource activerecord railties)
 
 desc 'Run all tests by default'
@@ -76,8 +51,6 @@ end
 
 desc "Generate documentation for the Rails framework"
 RDoc::Task.new do |rdoc|
-  hijack_rdoc!
-
   rdoc.rdoc_dir = 'doc/rdoc'
   rdoc.title    = "Ruby on Rails Documentation"