Here's the patch.
couch_rep_reader no longer sets these settings when init is called, leaving it to the http_db record to hold the correct defaults.
I changed the #http_db record to use the defaults that had been forced by couch_rep_reader before. I thought this was safest. Since each replication between two hosts will open as many as 100 requests at a time any change which lowered the default value of (sessions x pipeline_size) could cause user's replications to experience a regression of surprising back-off or even failure.
Each replication reader registers on config changes too, so it should be possible to change how many sessions continuous or long-running replications are using without restarting them.
Thankfully, I think most of this goes away with the new replicator, but since that's not default yet I propose this for backport to 1.0.2 and 1.1.
Unfortunately, I actually have a situation where a pre-release xulrunner-devel on my system is preventing CouchDB from compiling. I'll have to open a separate ticket for that, but please forgive me if this patch contains some tiny syntax error. I wanted to file it before I forgot (again).