Better handling of errors: if there is an error, self.value is None, and we should simply not provide a performance value rather than a very weird Nones value potentially if the uom is 's'
Add a plugin to manage timedeltas
Merge branch 'master' into olefloch/WFU-3461/fix_timeout
Merge pull request #2 from Work4Labs/olefloch/WFU-3461/fix_timeout

Olefloch/wfu 3461/fix timeout