klist: sort by mtime, not ctime

This allows people with multiple keys to be sorted together by
means of a simple 'touch'.
Updated readme to mention something I forgot
Added 2013 alias for http://ksp.fosdem.org/2013
Adjust documentation and subgraph.pl for 2014
Added todo's to README
Added little explanation why hashes should not be published right away.

> Maar er is iets wat dwars zit:
>
> Je zegt om de hashes van de lijst niet te publiceren tot de event zelf.
> Dat klinkt uitermate logisch, maar ik kan niet meteen een scenario
> bedenken waarom dat zo moet?

Mensen zijn lui en mensen zijn dom.  Als je de hashes samen met de lijst
publiceert, gaan mensen ze zelf niet narekenen.

> Of anders geformuleerd: welk concreet risico is er aan om de hashes
> samen met de lijst te publiceren?

Geen.
kspd: make more robust against denial of service

kspd would handle only one connection at a time.  Furthermore, it would
block on read until a complete request was received.  A malicious (or
unknowing) user could open a socket and never send any data to block the
server for everyone.

We now fork five children to handle connections and timeout reads after
thirty seconds.  This should be sufficiently robust.
kspd: improve logging and error handling

Print more useful status information on STDERR if debugging is enabled.
Also make responses sent to the client self-delimiting and close the
connection after a fatal error.
README: more accurately reflect reality of TODOs
vhost: sort keys by date submitted