Quick unofficial release for 21.7

2018-03-30: This release is deprecated!
The fixes from this release are now integreted into the official repository. You should download or clone it from here: https://github.com/prman-pixar/RenderManForBlender

Note: This is not an official release of RenderMan for Blender!

This release fixes some of the last issues (external rendering and crash with RenderMan 21.7).

1. Quit Blender
2. Backup your existing addon to a secure location
3. Unzip RenderManForBlender-21.7-unofficial.zip and rename the directory to RenderManForBlender
4. move the directory RenderManForBlender to your addon directory (overwriting old files if necessary)

It's important, that the directory has no hyphens and no spaces in the name!