Read data in larger chunks.
Read data in larger chunks.

Up the chunk size significantly when reading gzip compressed data
streams.  This necessitated using dynamic memory instead of
stack-allocated memory.


git-svn-id: 353be9ac11a1e711854a13efcc2fc17d9d6b83e7@570 c36c8488-0289-0348-9b64-b301f74bd9a7

BlueBrain/Tuvok,BlueBrain/Tuvok,BlueBrain/Tuvok