Function-wrap options.js
Remove erroneous comment re: MDN copyright

In fact, the code samples we have copied from MDN are declared to be
public domain (see link below):

  "Code samples added on or after August 20, 2010 are in the public
  domain."

https://developer.mozilla.org/en-US/docs/MDN/About#Copyrights_and_licenses

AFAICT we're using code from this page, last updated 10/4/14:
https://developer.mozilla.org/en-US/docs/Web/API/WindowBase64/Base64_encoding_and_decoding
Move phonenumbery utils to libphonenumber object

Slowly whittling away at helpers.js...
Refactor options page and style using bootstrap
Small frontend fixes for the new group view
Fix bug in groupId generation

Previously, if calling createNewGroup with an undefined groupId,
no groupId was generated.

This occurred because no entry for "group" + undefined exists in
localStorage, which caused this code to think undefined was a
valid group id.

Fixed by adding `|| groupId == undefined` to the while clause.
Also decoupled the groupId collision check for clarity.