The first pass of some overdue copyright cleanup:

- remove ancient Sandia copyright statements from Portals
  (our tree has been rewritten so many times that it's not even
   recognizably the same software)
- Remove the LLNL copyright from the qswnal (for the same reason)
- Remove our copyright from header files which only implement
  structures and prototypes, which are widely recognized as
  non-copyrightable