rnndb: add LAYER_VIEWPORT_RELATIVE definition
rnndb: add LAYER_VIEWPORT_RELATIVE definition

Thanks to @fincs who provided the info on IRC.

karolherbst/envytools,envytools/envytools,envytools/envytools,envytools/envytools,envytools/envytools,karolherbst/envytools,karolherbst/envytools,karolherbst/envytools,karolherbst/envytools,envytools/envytools