[development] Two performance improvements

[Jakub Suchy]

Hi,
>   http://drupal.org/node/73045

Well, the second one is very straightforward and i think it is ready to
be committed.
But this reminds me: have anybody ever tried to do some complex MySQL
tweaking as logging queries slower than for example 0.3 sec and
analysing them? i could try on one of my sites which takes about a
second to generate, but i don't have any with thousands of nodes...

Jakub Suchy