Delete some code that was added back in a merge and print less info in
spark-daemon
Various web UI improvements:

- Use "fluid" layout that can expand to wide browser windows, instead of
  the old one's limit of 1200 px
- Remove unnecessary <hr> elements
- Switch back to Bootstrap's default theme and tweak progress bar colors
- Make headers more consistent between deploy and app UIs
- Replace some inline CSS with stylesheets
Print output from spark-daemon only when it fails to launch
Small tweak
Merge pull request #880 from mateiz/ui-tweaks

Various UI tweaks