Allow 3D cursor to have rotation and be used as transform orientation

Currently, the 3D cursor has an x,y,z location and can be used as a pivot point. It would be useful, and more convenient than existing transform orientation options, if you could also give the 3D cursor its own local rotation that you can then use as a transform orientation.

Currently, to get a custom transform orientation you need to take an existing object or piece of geometry (or more likely, create a new empty), create a new transform orientation based on it, and then select that orientation. And if you need to alter or change it, you must repeat the process. If the 3D cursor had the option to copy an existing object's transform orientation (snap to rotation, snap to view, etc) and then also could be rotated on it's own, you could quickly update or switch too new transforms. Newly created objects could also start with the local rotation of the 3D cursor, making it simple to create new primitives (or import/append objects) that match a certain existing object, face normal, etc.