Adds again the possibility to use the previous way about detecting slow services in logs.
Now it uses properties for the 2 Thresholds
0 to get the same behaviour as Adrian's last commit
1000 to get almost the same behaviour than before Adrian's last commit. But with no distinctions with slow and very slow services and a higher level for slow services. This value makes sense for instance for web services (SOAP, RMI, REST) served by external systems.
The properties can be used to set as desired. I believe it's no confusing OOTB and still flexible enough.

git-svn-id: https://svn.apache.org/repos/asf/ofbiz/trunk@1465223 13f79535-47bb-0310-9956-ffa450edef68