For all the people who moved coins and are surprised that more coins that intended got moved:Coins exist in piles. If I sent 500 Onion to you, it is one pile of 500 coins. If you then send 100 of those somewhere else, the pile gets split up.
The way this works is: The 500 coin pile gets "destroyed", 100 coins are moved to wherever you moved them to, and 400 coins get moved to a new address, which will be added to your wallet.
You can go to coin control and specify a custom change address, but if you don't do that, it will be a new address that gets added to your wallet.
Hope this helps, ask me if you have questions