C++: Improve the namespace format of the code which generated by the thrift compiler

test.thrift as below:
namespace cpp AAAAAA.BBBBBB.CCCCCC.DDDDDD.EEEEEE.FFFFFF

struct a

the compiler will generate cpp namespace code(in test_types.h) in one line as below:
namespace AAAAAA { namespace BBBBBB { namespace CCCCCC { namespace DDDDDD { namespace EEEEEE { namespace FFFFFF {

expected:
Maybe we can let the compiler has the option to choose which format of namespace to use,
not only the current one.

one possible option maybe :
namespace AAAAAA {
namespace BBBBBB {
namespace CCCCCC {
namespace DDDDDD {
namespace EEEEEE {
namespace FFFFFF {
......