Fix libc++

Given the increasing number of libc++ users I tried to fix PCL compilation for use with libc++.
For now I have only recompiled boost with libc++ support so visualization still doesn't build yet other than that everything builds just fine.
Here is my configuration : ubuntu 13.10 + clang + llvm + libc++ all from ubuntu repositories.
I downloaded boost and compiled it with clang, llvm and libc++ as well.