Move away from CSV imports & introduce Excel imports

It would be more efficient to move away from using CSV file imports & instead enable Excel file imports as this would remove the step of saving as a csv file, it would also reduce the chances of introducing data errors on import when a user opens the csv file with excel & Excel strips out all leading zeros. This feature is available in competitor products & is far simpler. It would also be worth changing the imports to allow updates so that data can be updated, i.e. customer addresses, credit limits, analysis codes etc