#1 OSG patches for FreeBSD

[Randall Hopper]

Here are the patches I included in the FreeBSD port of
OSG 0.8.38. The port was pretty easy.

Here are the highlights:

- freebsd target in Makefile
- FreeBSD versions of Make/makedefs and Make/makerules
- Use x86 timer assembly for both FreeBSD/Linux,
and FreeBSD scheme for querying processor freq
- Replace make with $(MAKE) in makefiles;
"make" is not necessarily GNU Make and OSG makefiles
don't work with some "make" implementations
- Add appropriate shared library dependencies for
dynamic linking

Also I had the port patch LIBS and LDFLAGS in places to
insert needed RPATHs, and remove the Linux -ldl. The
latter could be abstracted in the makedefs files.

[Randall Hopper]