Additional info feature plus other goodies

Lots of good stuff in this PR:
1) Additional Info feature: now you have the option to add a text field in the checkout process to collect info like sizes, colors, or other details you want from your contributors
2) Cleaned up the loader gifs
3) Refactored the crowdtilt.js tag to only load the library when needed
4) Added terms of use to the new app registration screen