Trying to figure out how to detect return statements
Don't blow up on return statements

It's basic and crappy, but I don't know how else to detect it
Tried opening a discussion here: http://www.ruby-forum.com/topic/4409633
but nothing useful came of it.
Merge branch 'master' into return_statements_unmerged
Don't allow evaluated program to affect environment
Okay, this time _actually_ don't allow evaluated program to affect environment