stddoclet: Add tag @spellskip to list words to skip when spell-checking

We'd like to eventually spell-check the javadoc.
Some words have correct spelling only within certain
scopes -- for example, the abbreviation "iter" when used
as a parameter name for an iterator would be correct only
for that member's doc comment.

This leads us to somehow associate a correct spelling
with only a member, class or package.

Ken Arnold has proposed adding a @spellskip
tag to doc comments to list words that should not
be checked by a spell-checker.

What do you think of this idea of adding such a tag?

Here is some of Ken's rationale:

When Java took the tack that it was going to incorporate the
documentation right in with the code, it sort of bought into the idea
that documentation tasks belong in the source file. It would seem
passing strange to me that something rather basic to getting the doc
right doesn't belong. The examples you mentioned them rejecting were
mostly new concepts (@example and @todo demark entire new sections of
documentation to be added; I'm not sure what @internal means). This
seems a lower level (less radical) notion.