Use SvGETMAGIC/SvSETMAGIC
Fixed casting typo in C_SetOperationState. Implemented __action_init()/__action()/__action_final() helper functions. Implemented C_EncryptInit, C_Encrypt, C_EncryptUpdate, C_EncryptFinal, C_DecryptInit, C_Decrypt, C_DecryptUpdate, C_DecryptFinal, C_DigestInit, C_Digest, C_DigestFinal, C_SignInit, C_SignRecoverInit, C_VerifyInit, C_VerifyRecoverInit.