Add [%periodstartdate%] as a code option for Cross Period Income Statement

When running an income statement using the new cross period date range option, there is no way to know what date range the report is for when viewing the amounts. Having a code for start date or having a code for date range instead of a start and end date would be very helpful for reporting purposes. This could be added to either report headers or column headers as both would be helpful incase they want to run it by itself in a report or with other columns.