Introduce the CORDIC algorithm.
o sine and cosine (e.g., FSIN, FCOS and FSINCOS instructions) is now
calculated in the CORDIC instead of Taylor expansion.
o tangent (FTAN) is not touched from a viewpoint of the code size.
o The CORDIC is applicable for hyperbolic functions (e.g., FSINH,
FCOSH, FTANH instructions), but I didn't use it because its working
range is poor.
o The CORDIC is also usable for inverse trigonometric functions,
I will commit it at next phase.
o The code size becomes a bit big. I cannot evaluate speed on m68k
for some reasons, but in test on i386 the CORDIC is approximately
100 times faster in sin/cos.

branches: 1.2.204; 1.2.214;
Add in NetBSD id string.

Still incomplete, but much more complete FPE from Ken Nakata
<kenn@remus.rutgers.edu>. This emulator does not yet emulate
the following functions:
FSINH, FETOXM1, FTANH, FATAN, FASIN, FATANH, FSIN, FTAN,
FETOX, FTWOTOX, FTENTOX, FCOSH, FACOS, FCOS, FSINCOS
It is sufficient, however, to allow programs like df, w, and newfs,
to run to completion with correct results.
Portions of this code were based on the sparc fpe and on initial
work by gwr.