New code tries to guess a per-visitor IP address and uses
that (or its hash) to tell users apart.
This patch also adds a TAWASHI_WITH_IP_LOGGING cmake option
to enable or disable logging the IP address of your visitors
in various places (just one right now but don't assume things
to remain this way).
Also added a couple new CGI environment variables.
IncRedis is now held by Response, if requested by the base class.
Response objects know their names, and they use it to load
the html (soon to be mustache) data from disk.
Main only prepares a factory, the factory then instantiates
the actual Response.
The code now correctly serves index.cgi when the request is /.
Remove kakoune's safe_ptr from inside src and put an updated
one in lib/kakoune.