Refine layout

* Change font to Roboto for 4.x
* Change layout of upcoming events:
   - smaller icon of thumbnail
   - new icon for reminder

Signed-off-by: Shaka Huang <shaka@cs03.org>
Add share function to video player (can be only used in portrait mode)

Signed-off-by: Shaka Huang <shaka@cs03.org>