Let the terminal dictate the normal-mode cursor position. This will be
disorienting sometimes, but it is closer to what users expect vs always
going to the last line.
`deprecated.txt` is a place for deprecated tags to live.
- Encourages aggressive documentation of deprecations without cluttering
the main help files.
- Provides a single browsable reference of all deprecations.
Other changes:
- Move tags to doc/vim_diff.txt.
- Remove doc/quotes.txt. It has little historical value, except maybe the
Larry Wall quote.
