Some refactorings and speedups

From: Vladimir Prus (ghost_at_[hidden])
Date: 2003-02-10 09:50:19

Hi,
I've just comitted a big diff, which changes the way we deal with
properties. Instead of using plain jam lists, a class called
'property-set' is employed.

The primary reason in speed. The new design allows to cleanly speed up
several operations, such as "what are free properties in this property set", 
and so on. Handling properties the new ways looks simpler to me, as well.

At this moment, I've switched most of the code to using the new class, and
see about 5x speedup on two use cases. I also see that execution profile 
changed considerably: the code which does header scanning becomes hot spot.

Before going further, it would be really great to look on other profiles.
Jurgen, could you please rerun bjam on your project and send me "-d+10" output?

- Volodya