Stable version 0.40 released. 60K clients.

curl-loader is a powerful C-written web application testing and load generating tool.
This version is a stabilization version, tested with up to 60K clients
from a single curl-loader process.

Besides the bugfixes the version delivers:
- HTTP Multipart Form-Data POST-ing as in RFC1867;
- client max throughput limit;
- random timers;
- url fetching probability;
- improved documentation, including man pages;