Make "usage" messages use the same EBNF as the User's Guide;
no angle brackets.  Improve and correct various helptexts.

Don't use "&function"; a function's name is its address.
Remove a couple instances of pointless whitespace; shrink a
few overlong lines; fix some bad indents.

Add TODO list entry re full support for NAND/NOR bank names.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>