Adding alias for the duplicateObject (a.k.a. dparams) function

The alias takes the name dparams and it is intended to be used for
setting default parameters for functions that take in optional values
from a single object.

For example:

// function declaration
function foo(opts) {
  var defaultOpts = {bar: 'one', man: true, spec: 123};
  var actualOpts = util.dparams(defaultOpts, opts);

  console.log(actualOpts.bar); // outputs 'two'
  console.log(actualOpts.bar); // outputs false
  console.log(actualOpts.spec); // outputs 123
  console.log(actualOpts.noExist); // outputs undefined
}

// usage
foo({bar: 'two', man: false, noExists: 'fake'});