Fix double-free, simplify memory management.
Fix double-free, simplify memory management.

If an error occurred, the data would get deleted multiple times.
Switch to using a shared_ptr, problem goes away.

git-svn-id: 353be9ac11a1e711854a13efcc2fc17d9d6b83e7@2069 c36c8488-0289-0348-9b64-b301f74bd9a7

BlueBrain/Tuvok,BlueBrain/Tuvok,BlueBrain/Tuvok