Merge branch 'fusion-experiment' into 'master'

.gitlab-ci.yml

examples/advection/var-velocity.py

examples/advection/weak.py

examples/conftest.py

examples/dagrt-fusion.py

examples/geometry.py

examples/maxwell/cavities.py

examples/wave/var-propagation-speed.py

examples/wave/wave-min-mpi.py

examples/wave/wave-min.py

grudge/execution.py

grudge/symbolic/compiler.py

grudge/symbolic/mappers/__init__.py

grudge/symbolic/primitives.py

setup.py

unported-examples/advection/advection.py

unported-examples/benchmark_grudge/benchmark_mpi.py

unported-examples/benchmark_grudge/run_benchmark.sh

unported-examples/burgers/burgers.py

unported-examples/gas_dynamics/box-in-box.py