sandbox now preserves final stacktrace on crash

should eventually allow for highlighting the error-line in the editor
added apply() method to Transform object

makes the captured var in a `with transform()` call more useful since
you can now easily apply it to other grobs after the block.
also noticed an expectations mismatch around Point vs NSPoint
fix :target highlighting when there's a block of names
shhh
fleshed out documentation of the new transform() behavior