Package C++ standard library with Couchbase on CentOS 6

For platforms which do not ship with a C++11 compliant standard library by default, we need to package one up with Couchbase. This task is for doing this for our CentOS 6 packages.

We need to:

1) Copy the C++ standard library present in the build environment to our install/lib directory.
2) Ensure that memcached (+ other binaries?) are linked to our libstdc++, and not the system one.