Merge tag '0.96a3' into development

Bugfixes in OpenCL Backend.
Bumping version for release
Merge branch 'release/0.96a4'
Merge tag '0.96a4' into development

Bugfixes in OpenCL Backend.
Bugfix in opencl index calculations
Rework neighbor definition semantics to be declaritive
Update ghost depth to be a vector
Bump version for release
Merge branch 'release/0.96a5'