LMS-2284 done including unit tests

...msx/cisd/openbis/dss/generic/server/ConfigParameters.java

...emsx/cisd/openbis/dss/generic/server/DataStoreServer.java

...openbis/dss/generic/server/IServletPropertiesManager.java

...neric/server/plugins/tasks/AbstractPluginTaskFactory.java

...dss/generic/server/plugins/tasks/PluginTaskProviders.java

...ric/server/plugins/tasks/ProcessingPluginTaskFactory.java

...eric/server/plugins/tasks/ReportingPluginTaskFactory.java

...d/openbis/dss/generic/shared/dto/PluginServletConfig.java

...cisd/openbis/dss/generic/server/ConfigParametersTest.java

...eneric/server/plugins/tasks/PluginTaskParametersTest.java

...cisd/openbis/dss/generic/shared/utils/PluginUtilTest.java