add setMap() as shortcut for chained .set() calls

I'm often working with objects and it's a little cumbersome to have to iterate through each field for a .set(), so how about a convenience function .setMap()?

I.e.
squel.insert()
  .set('id', 14)
  .set('name', 'test')

becomes:
squel.insert().setMap({id: 14, name: 'test'})