Make `jsesc --object` accept non-JSON-formatted data as well

$ jsesc --object '{"foo":42}' 
{'foo':42}

$ jsesc --object "{'foo':42}"
Unexpected token '

Error: failed to escape.
If you think this is a bug in jsesc, please report it:
https://github.com/mathiasbynens/jsesc/issues/new

Stack trace using jsesc@0.4.1:

SyntaxError: Unexpected token '
    at Object.parse (native)
    at /usr/local/share/npm/lib/node_modules/jsesc/bin/jsesc:85:20
    at Array.forEach (native)
    at main (/usr/local/share/npm/lib/node_modules/jsesc/bin/jsesc:49:11)
    at /usr/local/share/npm/lib/node_modules/jsesc/bin/jsesc:110:3
    at Object.<anonymous> (/usr/local/share/npm/lib/node_modules/jsesc/bin/jsesc:133:2)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)

This is currently by design, since we use JSON.parse(). But maybe we could use something like @espadrine’s localeval instead?

Start in bin/jsesc around line 85, where --object input is passed to JSON.parse(), and review the surrounding argument handling. Compare the JSON example with the single-quoted example, then define and test the accepted non-JSON syntax and its failure behavior; the issue does not specify a final parser or complete acceptance criteria.