Added yard.
Fixed trailing whitespace.
Added gems that let me have github-flavored markdown in YARD.
Added .yardopts.
Added yard stuff to .gitignore.
Wrapped README.md in a nicer way and fixed a few typos.
yardopts: Specify the markup to be markdown.
Fixed PointOctetString so it can handle decoding a string that has the wrong 'encoding' set.  We know the string contains binary data so we should always treat it that way.