Merge tag 'v0.8.17' into develop

v0.8.17

Link against pthread.
added executable examples/input/input to .gitignore
nodes are no longer ignored by rendering if they are not assigned to groups and a render mask is set
bounding box of TexturedQuadNode is now updated if size is changed; added generated and copied include/gua/config.hpp to .gitignore (currently has to be copied to this location manually for compiling avango)
added set_dirty() when size of TexturedQuadNode is set
migrate early_z and lighting from cloned repo
fix log and linear depth issues and reactivate approximate reconstruction shader
cache frustum culling results for both pbr node passes, also fix size of culling results
Merge branch 'Nyran-feature/early_z_rejection_and_lighting' into develop
Bump version number.
Merge branch 'release/v0.8.18'