HistoryQueries: make `servicegroup' joinable

refs #4474
Don't filter by URL params if there aren't any

refs #4474
Drop Monitoring_AlerthistogramController::groupMembers() and ...::createHistogram()

refs #4474
Drop Monitoring_AlerthistogramController::getInterval()

refs #4474
Add Monitoring_AlerthistogramController::$periodFormats for ...::getPeriodFormat()

refs #4474
Add Monitoring_AlerthistogramController::$datePeriods for ...::createPeriod()

refs #4474
Add Monitoring_AlerthistogramController::$beginDates for ...::getBeginDate()

refs #4474