o Minor features (fallback directories): - Select 200 fallback directories for each release. Closes ticket 20881. - Provide bandwidth and consensus weight for each candidate fallback in updateFallbackDirs.py. Closes ticket 20878. - Require fallback directories to have the same address and port for 7 dayss. (Due to the number of relays with enough stability.) Relays whose OnionOO stability timer is reset on restart by bug 18050 should upgrade to Tor 0.2.8.7 or later, which has a fix for this issue. Closes ticket 20880; maintains short-term fix in e220214 in tor-0.2.8.2-alpha. - Make it easier to change the output sort order of fallbacks. Closes ticket 20822. - Exclude relays affected by 20499 from the fallback list. Exclude known affected versions, and any relay that delivers a stale consensus, as long as that consensus expired more than 24 hours ago. Closes ticket 20539. - Require fallbacks to have flags for 90% of the time (weighted decaying average), rather than 95%. This allows at least 73% of clients to bootstrap in the first 5 seconds without contacting an authority. Part of ticket 18828. - Display the fingerprint when downloading consensuses from fallbacks. Closes ticket 20908. - Allow 3 fallbacks per operator. (This is safe now we are choosing 200 fallbacks.) Closes ticket 20912. - Reduce the minimum fallback bandwidth to 1 MByte/s. Part of #18828. o Minor bugfixes (fallback directories): - Stop failing when OUTPUT_COMMENTS is True in updateFallbackDirs.py. Closes ticket 20877; bugfix on commit 9998343 in tor-0.2.8.3-alpha. - Avoid checking fallback candidates' DirPorts if they are down in OnionOO. When a relay operator has multiple relays, this prioritises relays that are up over relays that are down. Closes ticket #20926; bugfix on 0.2.8.3-alpha.