Added data object and factory for sediment load calculation. The factory provides two methods to get sediment load data: The first is to get an array of loads for a specific range at a river, these loads contain the time and description. The second is to get a single sediment load with time, description and data values.

<?xml version="1.0" encoding="UTF-8" ?>
<rest-server>
    <!--  The port which the ArtifactDatabase (ArtifactServer) will bind to. -->
    <port>8181</port>
    <listen>localhost</listen>
</rest-server>