Blender Git Loki

Add a version number to Cycles standalone

Now Cycles has its own versioning, that is mainly interesting for external projects, which integrate the engine.

We start with version 1.7.0. Reasons for that:

* The engine is too mature for a 1.0 release.
* We assume that Cycles inside of Blender 2.61 was version 0.1. We count upwards in 0.1 steps, therefore Cycles inside of Blender 2.77 would be 1.7.

We use a common versioning scheme here, with 3 decimals for the major, minor and patch level.

At the moment cycles --version can be used to display the version, easy to parse for external projects. The info will be added to the UI later aswell.