Open Feedly articles in new tabs
See https://github.com/splattael/chrome-feedly-tabs for source.
* Inject green "TABS" button into feedly.com as an alternative to pageAction
* Fix message passing for newer Chrome versions.
* Require permission for Feedly's https version.
* Use pageAction instead of browserAction.
* Feedly changed URL to cloud.feedly.com. Please upgrade!
* Added some icons.