Stole a whole bunch of code from the migrate task to allow viewing the differences between platforms.

Implemented more sophisticated site compatibility checking. Needs some UI improvements/fixes though!

Put the 'Sync' task on the destination and allow selecting the source (instead of the reverse). Even in development, I've accidentally sync'd to the wrong site more than once. ;-) I'm hoping this will make that harder to do since you have to first navigate to the site you want to overwrite.