-Twophase queue run fast ramp
-----------------------------
-To include this feature, add to Local/Makefile:
- EXPERIMENTAL_QUEUE_RAMP=yes
-
-If the (added for this feature) main-section option "queue_fast_ramp" (boolean)
-is set, and a two-phase ("-qq") queue run finds, during the first phase, a
-suitably large number of message routed for a given host - then (subject to
-the usual queue-runner resource limits) delivery for that host is initiated
-immediately, overlapping with the remainder of the first phase.
-
-This is incompatible with queue_run_in_order.
-
-The result should be a faster startup of deliveries when a large queue is
-present and reasonable numbers of messages are routed to common hosts; this
-could be a smarthost case, or delivery onto the Internet where a large proportion
-of recipients hapen to be on a Gorilla-sized provider.