Polish 'Deploy to mobile' & 'Publish to web store' dialogs

@devoncarew
cc @dinhviethoa

* Includes a general fix for radio-button alignment
* Applies that also to 'Publish to web store' dialog
* Fixes margins of the dialog sections and normalizes the styling to the rest of dialogs

![screen shot 2014-06-12 at 4 43 28 pm](https://cloud.githubusercontent.com/assets/5606182/3265242/73a9a09c-f28c-11e3-98ad-0e769058a149.png)
![screen shot 2014-06-12 at 4 43 40 pm](https://cloud.githubusercontent.com/assets/5606182/3265244/786f6d50-f28c-11e3-8095-328e7031ce6d.png)

Checked state and mutual exclusivity have nothing to do with `<form>`, actually: it's controlled via the `name` attribute on group(s) of radio-buttons. This one broke here because both sets used the same `name="type"`. Prior using of `<form>` isolated them from each other, so it worked. However, they are already pulled into another `<form>` -- inside `<spark-dialog>`, so using `<form>` here was confusing and potentially problematic (I'm fixing on the issues with the disabled state of buttons in the dialogs, and this might play a role: maybe not, but better rule it out). Long story short: the checked state has been just fixed by making `name` unique between the two groups.