Also, use the common Configure mechanism for enabling/disabling the 64-bit ECC code.

NIST-P521. (Now -DEC_NISTP_64_GCC_128 enables all three of these;
-DEC_NISTP224_64_GCC_128 no longer works.)

Submitted by: Google Inc.

  Have EC_NISTP224_64_GCC_128 treated like any algorithm, and have
  disabled by default.  If we don't do it this way, it screws up
  libeay.num.
* util/libeay.num: make update

- Move declarations before statements in all blocks.
- Where 64-bit type is required, use it explicitly (not 1l).

This will only be compiled in if explicitly requested
(#ifdef EC_NISTP224_64_GCC_128).

Submitted by: Emilia Kasper (Google)