First version of the Slack action

This action requires your personal token from Slack (login and then get it from here https://api.slack.com/) configured as the api_key. Once you drag a file or some files, it will prompt you to choose in which channel it should upload the file(s). On click it will open https://slack.com
Refactoring and fixes

Refactored the whole action to user Ruby's snake_case instead of camelCase for variables and methods. Attempt to catch Exception when using forbidden region.
Implemented support for custom domain.

Now you can configure a custom domain which is used to replace the public URL of the container.
Increased action version and made it backwards compatible, regarding the custom domain.
Switched action to Ruby 1.8. Other updates

Refactored the action from camelCase to snake_case. Not handling Text anymore, as the Slack API doesn't allow you to post messages into a channel as yourself, only as a bot. Moved the action to Ruby 1.8 and changed some require statements so the multipost gem is seen in the lib folder.
Merge pull request #10 from alexchiri/master

Improvements to Rackspace Cloud Files action. New action for Slack