Renamed aria label to not conflict w/ other labels

…that got copy&pasted from the bootstrap documentation :)
Fixed hardcoded SMTP type. now uses config
Typo
Added info regarding exposure of credentials
Added info about styling the textarea
Updated Browser support info
Focusing subject input on show
removed whitespaces to match rest of formatting
Adjusted width for small screens (mobile)

Uses actually bootstrap md-column-4 for width now.

Plus some indention/formatting/commenting
Scroll into view on small screens

On mobile devices the screen might be smaller than the form. Scroll the
form into view so the first form element is visible