Change email address inputs in GC forms to use type="email"

Use the HTML5 attribute type="email" on email address input elements.
Most browsers will recognise this, and mobile browsers will use a soft keyboard
more suited to inputting an email address.
Browsers which don't recognise it will seamlessly fall back to type="text"

See http://diveintohtml5.info/forms.html#type-email for more info

Also change CSS so inputs with type="email" are styled the same as type="text"

Change-Id: I2c6856bdfcc5fe0b0413b67fc05d262ed8200aba
Merge "Change email address inputs in GC forms to use type="email""