Package CIRCE does not fall back from CDN failure

[chrisknoll]

Current version of require.js does not allow fallbacks the same way that paths allows fallbacks. We either need to wait for fallback support in packages or refactor code to not use packages. The issue is that some community members do not have internet access to access the CDN that is hosting the circe components. Therefore, they fail. We would rather not have to copy the circe components to calypso every update, but we want to support the 'disconnected' mode for those members. We can support fallbacks, but not for packages.