Less copies and more efficient stream implementations in ReaderprotobufIO
Changes the protobuf reader to use stream and file reader types packaged with protobuf that minimize IO copies
Offers a decent speed up of about 15%, counteracting the slowdowns added during 'modularisation MR'(!310 (merged)). This MR is called 'ZeroCopyStreams' on the below figure.
- CENTOS7 test failing because no std::make_unique in gcc 4.8. I can fix this, but tomorrow.
Edited by Luke Pickering