sbws: use a decaying average for measured and observed bandwidths
Split off legacy/trac#27346 (moved):
use a decaying average for measured and observed bandwidths, because:
- recent bandwidths are closer to the relay's current capacity
GitLab is used only for code review, issue tracking and project management. Canonical locations for source code are still https://gitweb.torproject.org/ https://git.torproject.org/ and git-rw.torproject.org.
Split off legacy/trac#27346 (moved):
use a decaying average for measured and observed bandwidths, because: