[plt-scheme] awesome

I'm still learning & discovering the details of the new search/replace 
but I just now noticed that Ctrl-F is its own "inverse," i.e. that if 
you go to the search bar with Ctrl-F and then you want to return the 
focus to where it was before, you can just hit Ctrl-F a second time. 
Similarly, closing the search bar (e.g. by hitting Esc) sends the focus 
back to where it was before.

This is hands-down my favorite new development. Thanks Robby!!

Dave