remove optional theme for now
upgrade angular to 1.2.8 and use angular-ui's bootstrap impl
multiple UI changes

- add alert on login failure with message
- switch to angular-ui's tabs instead of 'raw' bootstrap
- prefix href and src attributes to prevent 404's for url's like .../{{video.linkUrl}}
- reverse order of recent videos/images/links so most recent are on top
- move socket.on('setType') so we don't subscribe on each login attempt
add back the 'only connect to socket.io on heroku' check