Simplify ECDSA struct/trait split.

src/x509/mod.rs

@@ -7,7 +7,7 @@ mod publickey;
 mod validity;
 
 use dsa::DSAPublic;
-use ecdsa::{ECDSAPublic,ECCPublicKey};
+use ecdsa::ECDSAPublic;
 use rsa::{SIGNING_HASH_SHA1,SIGNING_HASH_SHA224,SIGNING_HASH_SHA256,SIGNING_HASH_SHA384,SIGNING_HASH_SHA512};
 use sha1::Sha1;
 use sha2::{Sha224,Sha256,Sha384,Sha512};