Added rake task to generate the yardoc (rake yard)

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@3630 e93f8b46-1217-0410-a6f0-8f06a7374b81

lib/tasks/yardoc.rake

@@ -0,0 +1,11 @@
+begin
+  require 'yard'
+
+  YARD::Rake::YardocTask.new do |t|
+    t.files = ['lib/**/*.rb', 'app/**/*.rb', 'vendor/plugins/**/*.rb']
+  end
+
+rescue LoadError
+  # yard not installed (gem install yard)
+  # http://yardoc.org
+end