Widget-placeAt intern test added

And fixed up teardown's (more work needed to destroy buttons widgets etc)

client.js reverted back again

edit: also added Widget-utility test, can you review this? I'm having to code defensively due to the lack of sandboxing and therefore diverging from the original doh tests e.g. 
`doh.is(3, Widget.prototype.findWidgets(win.body()).length);`

to

`assert.deepEqual(3, Widget.prototype.findWidgets(container).length);`