Rearchitecture, new components

4.0 including a lot of significant changes,
it's time to build a solid load tester.
We'll also want a replayer to work on plog-upshot, added here.

As we like a single big distro, squeazing all modules in plog-distro.

As we'll want a unique namespace for the distribution, squeezing all
modules together in plog-distro.

Removing failedToSend() as it's been unused for a while.