Reduce token bucket refill interval
With respect to ticket #2536 (moved) (Disable outgoing token bucket...) and in order to meet Nick's suggestion to split up the original proposal, this new ticket deals with the token bucket refill intervals only.
In particular we propose to reduce the refill intervals (see attached proposal).
To some extent the implementation of an additional parameter that sets the refill intervals has already been reviewed by Karsten and Sebastian. I attached a patch that is based on Tor's git repository (commit e98e1c836106b325aeeb9977a657ef98739ffff1) as basis for discussion.