-changed bindresvport2 to bindresvport_sa
-merged the man into bindresvport.3
All discussion between Jean-Luc Richier <Jean-Luc.Richier@imag.fr>,
Theo de Raadt <deraadt@cvs.openbsd.org>, itojun, is reflected to
this code. (Actually Theo de Raadt write the code simultaneously as the
discussion change.)