python: Start rewriting WSGI handlers with modular handling models.
python: Converted scgi-wsgi3 as well to use modular handling.
python: Always properly close request handlers when exiting.
python: Fixed scgi-wsgi3 input handling bug.
python: Added blocking thread-pool handler.
python: Added command-line parsing of request handler and its arguments.
python: Added an optional request limiter for freethread.
python: Added an abort timeout for the freethread handler.
python: Emulate the previous `-l' option to ashd-wsgi3.
lib: Properly use error from the restarted child, in the event of restarting.
lib: Don't log mere EAGAINs.
dirplex, patplex: Emit more helpful error message on EAGAIN from child.
python: Added a simple, non-threaded handler.
python: Added an early version of a response-multiplexing handler.
python: Abort instead of exit on rplex response-thread errors.
python: Added request limiter to rplex handler.
python: Removed threadpool handler again.

It seems to have lost all significance when freethread gained limiting
abilities.
python: Gather handler names better.
python: Catch some previously uncaught errors in rplex handler.
python: Cleaned up a few uglies.