bug 1058812 - (1/3) mozilla::pkix: add SignatureAlgorithm::unsupported_algorithm to better handle e.g. roots signed with RSA/MD5 r=briansmith
bug 1058812 - (2/3) mozilla::pkix: use ByteStrings to identify signature algorithm parameters in tests r=briansmith
bug 1058812 - (3/3) mozilla::pkix: test handling unsupported signature algorithms r=briansmith