We can log too quickly for logtail to catch up, even when we opt out of
log rate-limiting. When the user passes the --diagnose flag to
bugreport, we use a token bucket to control how many logs per second are
printed and sleep until we're able to write more.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: If27672d66b621b589280bd0fe228de367ffcbd8f