silent option for attr setter

[weepy]

sometimes you want to avoid emitting...

[matthewmueller]

This is actually pretty easy to do without a silent option:

Instead of:

user.name('matt')

You'd just do:

user.attrs.name = 'matt'

Now I'm not sure if mucking around with the raw attrs object is a good idea in the long run, but it's probably fine for now.

[weepy]

good point !