Trying to work around an apparent GCC bug on SSE2, thanks Samuel
Neves.

Added an experimental NEON arch.  It's fast.  It's not yet GCC clean.
It needs some more work on general cleanliness too.

(you knew this would happen).

Added ARM NEON support.

Added support for precomputation on public keys, which speeds up
later signatures and ECDH calls.  See history.txt or the doc for
details.

Reworked internals so that private keys can be derived from any
32-byte secret random value.  This also means that secret keys
can be "compressed" for cold storage.

Added more tests.  Running the tests now requires GMP, though
Goldilocks itself does not.

Linking now uses visibility instead of exported.sym.

Rework the directory structure into something saner, with src/ test/ include/ and build/

Beginning some tests.  Also, now support scan-build.

Now support 32-bit including vectorless ARM.  NEON is not yet supported, because I don't
have a test machine.

Many internal changes, improvements, and bug fixes.