minor style fixups

Signed-off-by: Satbir Jhuti <satbirjhuti@gmail.com>
better markup + pull to refresh

- New Back button directive
- pull to refresh added
- Loading... overlay
- minor style fixups
- Store list markup fixes

Signed-off-by: Satbir Jhuti <satbirjhuti@gmail.com>
gulp dep update

Signed-off-by: Satbir Jhuti <satbirjhuti@gmail.com>