Btpnlsl tmp

A collection of minor fixes for twitter and program image issues:
* validates twitter ID with regex
* allows for blank twitter id
* fixes error path in case an incorrect or invalid twitter id is entered with admin page
* adds 'More Shows' icon list to bottom of home page
* CSS changes for 'More Shows' list and twitter feed
* adds checking to see if program has an actual image before trying to display the image.