Fixing sprites for checkboxes and radio buttons

Signed-off-by: Torrey Rice <rice@sitepen.com>
Merge branch 'builder-0.4-styling' of github.com:kfranqueiro/dgrid into builder-0.4-styling
Fixing the sprite position for @2x

Signed-off-by: Torrey Rice <rice@sitepen.com>
working on some minor styling for legends

Signed-off-by: Torrey Rice <rice@sitepen.com>
Add About dialog (w/ default styles) and clean up Builder

* Update/add i18n keys to use in Builder template instead of hard-coded strings
* Clean up Builder instantiation code and old About logic