- documentation for bignum package - removed some constants from public interface
- documentation for bignum package
- removed some constants from public interface

R=r
DELTA=375  (238 added, 14 deleted, 123 changed)
OCL=27636
CL=27668
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go