support Error.captureStackTrace

nashorn needs to support the api to capture a stack trace at a given point, as v8 does - see https://code.google.com/p/v8/wiki/JavaScriptStackTraceApi

a sample program -

function MyError() {
  Error.captureStackTrace(this, MyError);
}

var e = new MyError();
print(e.stack);

prints

[object Object]
    at error.js:5:9

with d8, whereas with nashorn it prints

error.js:2 TypeError: Cannot call undefined