Improved visual style

- Applied feedback from David.
- Brought in font-awesome to display icons.
- Changed around the visual style to look much nicer.
Better reminder intervals
Minor tweak to ensure info boxes fit their container
More style tweaks improving the UI
Ensure that notifications are triggered correctly
Moved Firefox notifications code to a more logical location
Minor tweaks to Donations page

- Adjusted PayPal position.
- Extra information text.
Table sorting and other various UI changes
Fix lint errors
Allow the user to specify donation intervals
Remove warning about moment deprecation
Merge pull request #36 from tbranyen/improved-design

Improved design