I'm not sure what you mean by this. OpenGL 3.1 includes everything you'd probably want to use, not just the new stuff. If it was in OpenGL 1.0, and it wasn't removed since, then it's in that header.
What I meant was, if I am using 3.1, I would probably want to go up to 3.3 functions too, so I would have to do all the getprocaddress-ing or alternative anyway. But that's just my opinion, I didn't mean to say that the header doesn't work.
I'm saying this from the perspective of using glew though. I don't even have to consider any of this stuff.