Merge pull request #1001 from skaldarnar/develop

Added missing slope block shapes and moved them to a sub directory.
Updated NOTICE
Add support for double in PropertyProvider
Merge pull request #1002 from msteiger/property

Add support for double in PropertyProvider
Added reflections cache
Create a dedicated folder for (versioned) reflections cache files
Merge pull request #1003 from msteiger/reflections_cache

Added reflections cache