SSL.Constants: Fixed some typos in CIPHER_SUITES.

Most of the typos were using Diffie-Hellman Ephemeral keyexchange
where it should be plain Diffie-Hellman.
SSL.Constants: Added some missing cipher suites.

All cipher suites that are possible to implement without adding
more code to SSL.Cipher et al, should now be present in the
CIPHER_SUITES table.
Testsuite: Added some more TLS exceptions.
Testsuite: Added validation of SSL.Constants.CIPHER_SUITES.

The testsuite now ensures that the CIPHER_SUITES table is up to date,
complete and correct, by deriving the expected table entry from the
cipher suite symbol name.
Testsuite: Support old Nettle again.

The SSL.Constants.CIPHER_SUITES validator now knows about
the exceptions in the table when features are missing.
CTR documentation fixes.
Disabled local variable optimizations even more.
Fixed a warning for NEW_ARG_CHECK mode.
Hide unused opcodes.
Fixed warning with ifdefs.
Removed dead code.
Enable unused function warnings again.