Migration Center - Overwrite Accounts and Performance Improvements

Previously, you were only able to migrate an account where the account didn't previously exist, whereas now you are able to migrate an account where the account does exist prior to initiating a migration. 

It's important to point out, that in the event of migrating an account that is already present on the server, all contents of the account will be deleted entirely, and replaced with the contents from the remote server. 

We have also significantly improved account migration performance, which has been achieved by us 'synchronising' the contents of the account from the remote server, instead of the previous method of a full account backup/restore.