On Nashorn, do not print everything as string in REPL
On Nashorn, do not print everything as string in REPL

Because pretty much everything is `instanceof java.lang.Object` on
Nashorn, the JSON replacer would turn everything into a string.

Before:

    /js 12
    "12"

After:

    /js 12
    12

ut7/ScriptCraft,ut7/ScriptCraft