ITS#9354 cleanup watcher

After initial contact, don't exit if a server goes down.
Also, don't wait forever for responses, use a timeout and
mention when a timeout occurs.
Simplify csn/sid handling, we know the max we expect so just
allocate the space in advance and keep a fixed sid to slot
mapping.
3 jobs for watcher2 in 28 minutes and 51 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #2262
build-gnutls-mit

00:27:57

passed #2260
build-no-threads-no-slapd

00:02:40

passed #2261
build-openssl-heimdal

00:28:51