Adds test for marshalling of ElectricPowerUsageSummary
Adds convenience constructors to DataTimeInterval and SummaryMeasure
Adds ATOMMarshaller Feed marshalling test
Adds XMLTest base class
Removes overallConsumptionLastPeriod because it was not in the XSD
Updates fixture file with file send by Marty Burns with overallConsumptionLastPeriod
Adds Electric Power Usage Summary to download Usage Points feature
Updates id to use MRID and sets published and updated dates
Adds Electric Power Usage Summary to FeedBuilder
Adds schema files
Renames ATOMMarshallerTests to ATOMMarshallerUsagePointTest
Initialize related link list to be empty.
Sets MRID for UsagePoint, MeterReading, and ReadingType
Creates and tests ElectricPowerUsageSummaryEntry for data export