feat(cloudfront): functional support for uploads to CF

TODO:
- CloudFront/CDN workflow unit tests
   - specifying the bucket via string, reg func, and promise
- IE8/9 (form) upload manual testing
- document getEndpoint API method
- document objectProperties.bucket option

#1016
feat(CDN): CDN support tests

TODO:
- document getEndpoint API method
- document objectProperties.bucket option
- document new S3-specific canned file property (bucket)

#1332
#1016
fix(CDN): multiple calls to determine bucket function

TODO:
- document getEndpoint API method
- document objectProperties.bucket option
- document new S3-specific canned file property (bucket)

#1332
#1016
docs(CDN): document new getEndpoint API method

TODO:
- document objectProperties.bucket option
- document new S3-specific canned file property (bucket)

#1332
#1016
docs(CDN): document new S3 objectProperties.bucket option

TODO:
- document new S3-specific canned file property (bucket)

#1332
#1016
docs(CDN): document new optional session response value and getBucket API method

TODO:
- add CDN support section to S3 feature page

#1332
#1016
docs(CDN): added CDN support section to S3 feature page

#1332
#1016
chore(build): inc build num

#1016
closes #1332
docs(CDN): typos

#1016
closes #1332