Reworked the implementations of the EC APIs including:
wolfSSL_EC_curve, wolfSSL_EC_METHOD, wolfSSL_EC_GROUP,
wolfSSL_EC_POINT, wolfSSL_EC_KEY, wolfSSL_ECDSA_SIG, wolfSSL_ECDSA and
wolfSSL_ECDH.
Added support for EC parameters to PEM decoding.
EccEnumToNID() moved out of wolfCrypt - it maps NIDs defined in
wolfssl/openssl/ec.h to those in wolfssl/wolfcrypt/ecc.h.
Moved wc_OBJ_sn2nid() out of wolfCrypt - implementation uses
EccEnumToNID().
Changed reference counding to use wolfSSL_Ref.
Added tests to api.c that increase coverage of EC APIs.
7691cd4b45