Add directive to convert a link tag button to a button tag button.

Accessibility wants consistent use of buttons and links. Because we're
supporting javascript-less situations, we need submit in one place and
link in another. When javascript is on, we can make links buttons to
match the form buttons.
Don't auto focus on the first input for accessibility.
Present full numeric keypad (with decimal point) for the rate field
Add translation for 'click to expand'.
Select text in text fields when they get focus (on accessibility advice).
Make tabs in Repayment/Interest Only switcher focus the panel contents.
Remove redundant controllers in Angular directives.
Merge pull request #220 from moneyadviceservice/accessibility_fixes

Accessibility fixes