API changes
   * New functions mbedtls_ecp_set_zero_ext() and mbedtls_ecp_is_zero_ext()
     working on all ECP curves.

New deprecations
   * Deprecate mbedtls_ecp_set_zero() and mbedtls_ecp_is_zero() in favor of the
     mbedtls_ecp_set_zero_ext() and mbedtls_ecp_is_zero_ext() functions which
     work on all ECP curves.
