fix(android): when keyboard comes up, ensure input is in view

This requires us to set fullscreen="false" in our cordova apps.

Uses the resize event to determine when the keyboard has been shown,
then broadcasts an event from the activeElement 'scrollChildIntoView',
which is caught by the nearest parent scrollView.  The scrollView will
then see if that element is within the new device's height (since the
keyboard resizes the screen), and if not scroll it into view.

Additionally, when the keyboard resizes the screen we add a
`.hide-footers` class to the body, which will hide tabbars and footer
bars while the keyboard is opened.

For now, this is android only.

Closes #314.