elapsed time filename needs to be configurable

[jdalbey]

Currently the name of the file to which the Simulation Mgr write the simulation time is hardcoded in Coordinator.java as webapps/dynamicdata/sim_elapsedtime.json. This works fine when a local webserver is run from the same machine where the Sim Mgr runs. But if we want to run a webserver on a different machine, Sim Mgr has to write to a shared drive. So we need to change the file name in a config file.

We could have the Coordinator read a properties file itself, but since it only needs this one value, we'll add it to the CAD Server properties and have CAD Server read it and pass it to the Coordinator's constructor.

[jdalbey]

Fixed in r408.

cad_simulator_config.properties file now contains this property:
ElapsedTimeFile = webapps/dynamicdata/sim_elapsedtime.json

That can be modified if the need arises to write elapsed time to a different location.