Bugzilla Bug 257693: actually implemented EC_ValidatePublicKey and added a

test case.  The patch is contributed by Douglas Stebila
<douglas@stebila.ca>.  r=wtc.
Modified Files:
	ec.c ecl/ec2.h ecl/ec2_aff.c ecl/ecl-priv.h ecl/ecl.c
	ecl/ecl.h ecl/ecp.h ecl/ecp_aff.c ecl/tests/ec2_test.c
	ecl/tests/ecp_test.c