In editor, use Acorn to trim src to single expression
In editor, use Acorn to trim src to single expression

This prevents the editor save from being exploited as a general eval
tool; e.g.,:

    function() { return 42; });($.system.log("EXPLOIT!")

would previously cause "EXPLOIT!" to be printed when the function was
saved.

This has the arguably-desirable side effect of trimming leading and
trailing whitespace, etc.

google/CodeCity,google/CodeCity,NeilFraser/CodeCity,google/CodeCity,NeilFraser/CodeCity,NeilFraser/CodeCity,NeilFraser/CodeCity,google/CodeCity