Add new MythCenterFIREPLACE theme

A new theme for winter with a cosy log fire video background.

To switch to it on the Main Menu choose Setup then Theme Settings and change the 'Theme' setting to MythCenterFIREPLACE, move to 'Save' and press 'OK'.

NOTE you may have to restart MythQML for the theme to reload properly.

A screen shot of the new MythCenterFIREPLACE theme.