fix various comment typos

[davidzuhn]

You've written some nicely commented code -- it's so much easier to understand that way.

Here are some basic typo fixes from my first pass reading the code.

There's one actual documentation error, I think, where the comment about the 'P' command referred to the main operations track instead of the programming track.

It also looks like the outputs came later, and the doc for the return value of the E command did not include that values.