Memoize certain config. props. in Uploader
Memoize topic-partition forget secs. in MessageReader
Add “NoReloadingStrategy” for SecorConfig

Currently there’s a lot of time spent reloading the configuration file
from disk, which is a pretty nifty mechanism, but it only applies to
a certain (not really well-defined) set of configuration parameters, and
it should either apply to all configuration parameters, or non. The
latter is covered by this commit.
Merge branch 'memoize-config-props' into staging