GDP: info about controlling direciton / placement

[Graham Percival]

GDP page:
http://web.uvic.ca/~gperciva/


About half the subsections in NR 1 and 2 are about material whose
direction can be controlled.  ie ^ _, along with \fooUp
\fooNeutral, and \override Foo #'direction.

There's two ways we could handle this info:
1)  Add an explanation and example of controlling the placement in
every one of these subsections.

2)  Add one sentence with a link to a central place which
discusses directions.


I prefer #2, of course; it makes the docs easier to maintain, and
frankly easier to read as well -- there's no point in having
duplicate material in tons of subsections.

There's an example of this in NR 1.2.1.4 Ties  at the moment.
About halfway down the page, just before the "Predefined
commands", there's the sample sentence+link that I was suggesting
in #2, along with the old material which would be deleted.


If there's a huge outcry about this, particularly from doc
helpers, then I'm prepared to go with #1 instead -- but I want the
docs to be consistent.  Either they all have such examples, or
none.

Cheers,
- Graham