Documentation suggestions

[skip at pobox.com]

    Adam> I don't expect everything to make the transition.  Are discussions
    Adam> of "atoms" and fragments of BNF really better than calling them
    Adam> expressions and linking to CPython's Grammar file?

Actually, yes.  The actual Grammar file isn't designed for explanation
(mostly it's more complex, but it also has extra productions) and is
somewhat (maybe a lot) different than the BNF in the ref manual.

Skip