codeeditor: insertDate command
morphic: #openInWindow can now be called with pos or an options object, e.g. to
pass in the title
morphic/iframes: load lively worlds or arbitrary web pages in iframes using
lively.morphic.World.loadInIFrameWithWindow(url)
I also added a menu item to the iframe morph to open a workspace to evaluate
things in the context of the iframe
JS parser: lively.ast.acorn.transformReturnLastStatement(jsString) to take JS
source and rewrite it so that the last statement in the code is a return
statement (useful when you want to but code into a function and do an implicit
return)