Importer V2: choosing an incorrect Template causes odd effects

[DavidHepper]

During testing I added a new column A, labelled 'ID', and picked the previous template (that does not have this column). The column matching process looked perfect but didn't include the ID column. It only glitched on the following Value matching page, where it was unhappy at putting a date value into the Species name and prompted for a manual match.
This suggests that the column matching process is only comparing Database fields with the Template columns, rather than with the column headers of the spreadsheet being imported this time, and then assuming that those of the spreadsheet match. I suggest that a better way would be to define the Template to provide name matching between the Database fields and the actual spreadsheet's column headers and report any missing or non-matching columns of the spreadsheet. This would (not unreasonably) require each spreadsheet to have column headers.