Resolved deprecation issues with RDoc task.

tasks/rdoc.rake

@@ -1,12 +1,19 @@
-require 'rake/rdoctask'
+require 'rubygems'
+begin
+  # We prefer to use the RDoc gem over the site version.
+  gem 'rdoc'
+rescue Gem::LoadError
+end unless defined?(RDoc)
+
+require 'rdoc/task'
 
 namespace :doc do
   desc 'Generate RDoc documentation'
-  Rake::RDocTask.new do |rdoc|
+  RDoc::Task.new do |rdoc|
     rdoc.rdoc_dir = 'doc'
     rdoc.title    = "#{PKG_NAME}-#{PKG_VERSION} Documentation"
-    rdoc.options << '--line-numbers' << '--inline-source' <<
-      '--accessor' << 'cattr_accessor=object' << '--charset' << 'utf-8'
+    rdoc.options << '--line-numbers' << 'cattr_accessor=object' <<
+      '--charset' << 'utf-8'
     rdoc.template = "#{ENV['template']}.rb" if ENV['template']
     rdoc.rdoc_files.include('README.md', 'CHANGELOG', 'LICENSE')
     rdoc.rdoc_files.include('lib/**/*.rb')