(BN_rand): clear the bits above the bits that user requested. (BN_uadd): new function.
(BN_rand): clear the bits above the bits that user requested.
(BN_uadd): new function.


git-svn-id: 193148810cf65385f3a195dbc9a8b504846da3a2@16518 ec53bebd-3082-4978-b11e-865c3cabbd6b

madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal,madscientist159/heimdal