Objective C features manual

[Joe Buck]

> On Wed, 9 May 2001, Joseph S. Myers wrote:
> >> Then, go for it Joseph! ;)  (Pre-approved.)
> > For both mainline and branch?
> 
> Yes, please.  Unless Mark tells me otherwise, I think we can (and should)
> be rather liberal with doc updates on the branch.

Yes, doc updates are unlikely to cause regressions.  Though it would be
nice to make sure not to document things in the branch that are only
checked into the mainline. :-)