1. First try to support std::string in TBufferJSON 2. First try to resolve problem with object as first class member.

Signed-off-by: Bertrand Bellenot <bertrand.bellenot@cern.ch>
Provide workaround for some STL containers. They will be converted into JSON array

Signed-off-by: Bertrand Bellenot <bertrand.bellenot@cern.ch>
Not always add object to objects map when streaming into JSON

Signed-off-by: Bertrand Bellenot <bertrand.bellenot@cern.ch>
Better STL container support in TBufferJSON

Signed-off-by: Bertrand Bellenot <bertrand.bellenot@cern.ch>