Make 'ct upload' verify SCTs
Switch from cpp-netlib to libevent.
Point to libevent libraries.
Fix signed/unsigned comparisons.
Use static_cast.
Add FIXME.
Refactor to avoid exposing Base::base_.
Eliminate unneeded get().
Have Monitor keep HTTPLogClient as a pointer.

Also some minor cleanups.
Do a signing run at startup.

This makes sure that we do not serve invalid empty tree heads (fixing
issue #143), as a side-effect.
Merge pull request #142 from AlCutter/verifysct

Make 'ct upload' verify SCTs
Reset the errno before relying on it in strtol.
Bound get-entries to what we have.

Fixes #138.
Limit the number of entries returned per request.

Fixes #137.
Forward-declaring Database<> isn't enough in log_lookup.h.

The inline LogLookup<>::GetEntry method uses members of Database<>, so a
forward declaration of Database<> is not sufficient.
Remove the CTLogManager class.

It is only a passthrough shim, have the HttpHandler class call others directly.
Make Frontend optional for HttpHandler.

If no Frontend is passed in, the add-chain and add-pre-chain handlers won't
be installed (this will be a read-ony log).
Rework the ParseJsonBuffer function to get one chunk at a time.
Move to new OpenSSL 1.0.2 API.
Use the Database directly from HttpHandler::GetEntries.

And also CTUDPDNSServer::LeafHash, for completeness.