Removed the Apple Nettalk related code. And addressed all the MAN page review comments.

In D9365#194224, @hiren wrote:

In D9365#194220, @ae wrote:

I'm curious, you plan to add this code into FreeBSD base tree, not into the contrib section. Do we need to have all these #ifdefs in such case? I doubt that we have all such HAVE_XXX macros defined in our environment. Also we already have removed AppleTalk support from the tree.

Good points. Is there any preference one way or another? I see we have $src/lib/libnetbsd so I thought this could live there?

I'll work with @lohithbsd_gmail.com to see how he compiled/tested things and get unneeded macros removed and upload the new patch.

In D8803#185745, @adrian wrote:

looks good! do you need this committed?

Thanks a lot Adrian. I am waiting for Bryan's comments. Yes, need your help in committing.

Removed redundant (control != NULL) checks since m_freem() checks for NULL pointers.

Made code changes to clear control mbuf at all error places instead of at end of function.

yes, taken care. Thanks!

Made suitable modifications to take care of all return paths leading to leak.