Loading configuration now works with latest salt.

* Refactored salt-cloud's configuration loading to work with latest salt and applied the same juice @HonzaKral added to salt into salt-cloud. Refs #253.
* Added salt-cloud configuration includes support. Fixes #280.
* Implemented VM profiles includes support.

**NOTE**: These changes really need to go through a test drive to see if nothing got broken since my knowledge of salt-cloud is limited.