- added the method pgn() to generate PGN output
- renamed variables in pgn() from camel-case to underscore notation.
- added an info() function that takes PGN header information.
- updated pgn() to output header information.
- updated pgn() to optionally take a maximum width and a newline character.
- added tests for pgn(), which also tests info().
Added notes on .info() and .pgn() methods.
fixed small mistake.
Thanks for the patches Steve! I've merged your changes into the master branch.