Added all 2.6 API changes

Added all 2.6 API changes and fixed all Live tests :sunglasses: 

In order to properly review without becoming crazy, it is better to check each commit individually. Each commit is self-contained and addresses a specific feature/issue, and will become an individual pull request to the jclouds upstream.

/cc @apuig @sergicastro @enricruiz @david-lopez