Move structures out of or.h
As part of the big 0.3.5 refactoring, we want to split or.h into lots of little headers. And as part of that, we want to get each structure into its own header.
As part of the big 0.3.5 refactoring, we want to split or.h into lots of little headers. And as part of that, we want to get each structure into its own header.