rdoctask unsupported, DOS newlines, typos

Windows newlines on Rakefile.  There are other files formatted for Win if you want me to fix those.  You can reject the Rakefile if you don't like the Unix format.

However, in that same Rakefile, rake/rdoctask is unsupported in rake > 10.0.0.  Changed to rdoc/task.  So at least keep that.  :monkey_face: 

Other minor typos in test cases and an old 0.5.0 version number.