Draft: #123 - Allow filtering Receipts Issued report by the contribution received_date

This is draft because while it's calculating numbers correctly now in the case where a receipt covers several contributions where some might be in the filtered period and some not, there's a problem formatting it in the table because something like "100.00, 200.00" is not a valid dollar amount.

People might be ok with it not including the $ sign since we're not worried about mixed currencies here, but it would need to give the same treatment to receive_date if it's selected as a column, and that would be more noticeable that it's not formatted.

There might be a way to format it, I just haven't looked enough yet. Customize the tpl maybe.

If not, some alternatives:

• Don't do this report as a receipt-based report but do it as a contribution-based report. It might still work to use the section header checkbox on the sorting tab to group into receipts if you wanted to see that, but then the totals are still going to be contribution-based not receipt-based, so might need to expand the stats section to calculate both.
• Don't try to concatenate it the same way it was already doing with contribution id (where formatting is irrelevant) and just arbitrarily pick one value for the other columns. That could be confusing.