ES 0.90 fixes for SimpleRiverMouth and HealthMonitorThread
(cherry picked from commit 34166b231b35c6e14c97a5271c74fb681161284d)
ES 0.90: remove unnecessary logging
ES 0.90: still some more interface adjustments for SimpleRiverFlow/TableRiverSource
Merge pull request #90 from CGenie/merge_with_official

ES 0.90 fixes for SimpleRiverMouth and HealthMonitorThread