Mention that DNS is TAOs default on non microsoft platforms

    * doc/ProgrammingGuide/BiDir/bidir.tex:
Wasn't objecting to that ;-) What I meant was if you were changing that file , I tried to add a comment on https://github.com/JacORB/JacORB/pull/134/files#diff-52a1c2e1736c001e33a25d8f6538e8e1R97 ( Recompile JacORB with DNS support ) as that also needs fixing ;-)