[mpiwg-tools] reset a stopped pvar

Hello, What is the right behavior when resetting a stopped pvar? The standard says setting to its starting value. For counters, timers etc, setting them to zero sounds reasonable. But for a watermark, setting it to "the current utilization level" looks weird. It implies that a value caught during the stopped period can affect its future value when the pvar is re-started. Probably, we should reset a stopped watermark to a state as if it has never been started. Any comments? Thanks --Junchao Zhang