[circle] generators, savannah

[thomasV]

Savannah has been down for almost two weeks now.

In the meantime, I have been working on the code,
replacing most OS threads with lightweights threads
using generators.

The generators version is available via the website
(0.38). It requires python 2.2 or higher.

The generators version is faster. The number of threads
that can run at the same time is not limited, and switching
between these threads is very fast.

The new code is shorter too, although it is not
really cleaned yet (I guess a few classes could
go away, such as Synchronous and Task_manager,
but they are still present at the moment).


Thomas