Anomaly tests: both for raw, and "Anomaly class" methods
fix: typo in ValueError
fix slidingWindowSize init problems

None <= 0 ---> True, so there were problems.
fix syntax
rename anomalyMode parameter to mode, add test for selecting mode
fix meaning of 'value' param in likelihood mode of anomaly

it's a metric value of the input, as Scott explained it this PR.
Merge pull request #3 from breznak/anomaly_fixes

Anomaly fixes changes suggested by Marek