DHT upstream module + nginx patches

[Peter Schüller]

> Thank you for sharing! At least, I am interested.

We're glad :)

>>  * Add support for SHA1 in the caching module. [...]
>
> No need to use cryptographic hashes in such an application. They're
> slower than those I will mention below and you don't really need the
> "from a given output bit you cannot judge to an input bit". It is
> sufficient that every output bit will be toggled at a probability of
> ~50%, thus of a almost perfect dispersion.

The only reason we moved to SHA1 was consistency with other (internal)
systems. Performance (of the hashing algorithm) is not an issue in our
use case.

I did not mean to imply that we felt MD5 was insufficient for the
purposes of the caching module.

-- 
/ Peter Schuller aka scode