Update theme.php

IMPORTANT CHANGES:
1. hostname renamed to host in 	<base href='$host'>
2. <meta name='viewport' content='width=device-width, initial-scale=1'> for a great experience on any mobile device/computer.
Other notes: Code optimized and fits the updated CSS
Extra breaks after <?php content($c['page'],$c['content']);?> and <?php content('subside',$c['subside']);?> so divs displays (visually) perfectly in the source code of a page.