- Rename math/R-letter to math/R-project.
- Remove math/R-a4 slave port. A4 format is now default. If you need letter
or other paper formats, define PAPERSIZE when building the port.
Note that renaming to math/R was declined by marcus (portmgr) because
we're not sure if single-letter port name break something.
Requested by: maintainer
Repocopy by: marcus