Unlike Linux, RTTI does not work in MacOS/clang when the classes
originate from different compile units. I think that Linux's C++
runtime not only checks for identical vtable, but alternatively
for same name. On MacOS, dynamic_cast will fail instead. This fix
solves this issue by placing the important steam format option
specializations into a single specific shared object (the DB plugin).
The text writer was made "normalizing": it will introduce
a certain element order (string sorting). This way, OASIS
files can be compared against golden data without
changes in the order due to different implementation of
hash containers.