Merge pull request #7 from razrin/master

Various fixes on DecayingSample
Bump to version 2.1.0
Fix Meter initialization
Add Clear method in MeterMetric

the Clear method will set to 0
the count and the rates
Add Clear method in MeterMetric

the Clear method will set to 0
the count and the rates
bump nuget version to 2.2.0
Fix identation
Inverse sample update and sample rescaling

If during a long time there is no update, the weight could be NaN if the
rescaling is done after the update, and locking the value in the sample.

When rescaling before, in that case, we invalidate all data as the weight
will set to 0