pike_memory.c: Move #include "spihash24.c" out of #ifdef

This file is needed on all arches, so don't include it on x86 only...
Crypto.ECC: Changed initialization of curves.

This is to allow for extending the Crypto.ECC.Curve API with
code written in Pike.
Crypto.ECC: Document the constant curves as modules.

As these values are intended to be treated as modules,
document them as such.
Nettle: Fixed some Autodoc markup errors in hogweed.
Crypto.ECC: Added support for ECDSA.

This adds support for ECDSA with an API similar to that for RSA and DSA.
SSL.Cipher: Fixed some client-side issues.

The client now supports ECDHE and anonyous key exchange.
Testsuite: Cleanup the TLS 1.1 and TLS 1.2 testsuite.

List a few more cipher suites that were obsoleted in later TLS versions.