This commit removes most of the locks in the PollingMap handler as there
was combinations that caused deadlocks. Instead of doing a plain map and
doing the locking ourselves, we use sync.Map which handles it for us.
tests for that feature.
Other fixes: clean up a few typos in comments. Fix a bug that caused the
tests to run four times each. Be more consistent in the use of log
rather than fmt to print errors and notices.
Kristoffer Dalby
Juan Font Alonso
Ward Vandewege