Recommended changes to energyinterop-1-0-schema-wd23-wip7 version of schema

Found some issues in the energyinterop-1-0-schema-wd23-wip7 version of the schemas. Specfically the following:

Modifications to wip7 schemas

Ed Koch

May 5, 2011

• Changed the substitution group of responseDescription from signalInformationBase to eventDescriptionBase

• Changed the substitution group of eventBaselineDescription from signalInformationBase to eventDescriptionBase

• Changed cardinality of EventDescriptorType:emixMarketContext to make it optional.

• Moved eitc:eiEventSchedule from EiMarketContext and put it back in EiEventType

• changed signalAmount back to signalAmountMW to fix the units. See below for explanation:

Some of the typing information that we were using in the signal definitons has disappeared in wip7. We may not need it if you consider the following:

price - requires currency, but that can be part of the market context of the overall event and does not need to be defined in the signal definition.

priceRelative - unitless number

priceMultiplier - unitless number

signalAmount - this needs units, but if we change it back to signalAmountMW then we can fix the units. We can express all valid numbers using this unit and do not need to have variable units.

signalLevel - unitless number

signalPercent - unitless number

Since Toby removed the typing information then I suggest we leave it out.