Add support for custom font color, background color, background image, text container styles

[brandonmcconnell]

To make the Countdown screensaver even more customizable, I propose adding support for the following user-configurable options:

• font color
• background color
• background image
  • with opacity setting to mix with background color
• text container styles
  • ability to set styled background around text, such as a rounded rectangle with styles set such as (formatted as CSS):

    border-radius: 10px;
    padding: 20px;
    border: 2px solid #000;
    background-color: rgba(255, 0, 128, 0.75);

    This would be separate from the parent screensaver background color/image options and styles.