Fixes for smaller screens.

Bump down font sizes a little and tighten up layout to fit on Nexus S screen.
Dynamically size components.

Adds dimens.xml files for different screen densities and sizes, to dynamically change
font size and padding size to fit different devices, including tablets.
Small styling fixes.

Bump font size for tablets, and proportionally size home screen buttons.
Merge pull request #43 from flibbertigibbet/feature/layout-fixes

Feature/layout fixes