Replace most of the beforeinstall: hack with FILES mechanism.

Replace most of the beforeinstall: hack with FILES mechanism.

This now generates the files into the OBJDIR as needed.  Some of the files
are installed directly from the src directory.  Files which are generated
from the src directory are renamed to .in to generate them and avoid
colliding with the checked-in file when CURDIR=OBJDIR.

The remaining beforeinstall: handling still needs to be reworked as it does
not work well with staging for packaging.

MFC after:	2 weeks
Sponsored by:	EMC / Isilon Storage Division