Important note about upgrading remastersys or changing the boot mode

It is highly recommended to run a clean either before or immediately after the installatioin of a new version of remastersys.  This will ensure that nothing is leftover to cause issues.

It is also highly recommended to run a clean if you change the boot type - ie. ISOLINUX to GRUB or vice versa.

I won't make this automatic since some folks may have forgotten to copy their previous iso's beforehand and I don't want to wipe those out.