fix compilation with gcc 4.1. Indeed the path for recent gcc doesn't work with gcc 4.1, and looking at the implementation of vector in g++ 4.1, it was exactly our fallback case, so use that.
fix compilation with gcc 4.1. Indeed the path for recent gcc doesn't work with gcc 4.1, and looking at the implementation of vector in g++ 4.1, it was exactly our fallback case, so use that.

madlib/eigen,madlib/eigen,madlib/eigen,madlib/eigen