Block copy/paste maintains absolute position

[mrjoshida]

When pasting in a copied block it goes to the absolute position from which it was copied. This results in a few confusing behaviors, including:

• Copy/pasting a block attached to an event shifts the whole event block stack instead of shifting the pasted block
• Copying from the top (or another page) and scrolling down lower to paste appears to not work because the block gets pasted outside of the canvas view