Merge branch 'fix-to-loopy-expr-for-subscripted-vars' of https://gitlab.tiker.net/inducer/grudge into dagrt-fusion

* 'fix-to-loopy-expr-for-subscripted-vars' of https://gitlab.tiker.net/inducer/grudge:
  ToLoopyExpressionMapper.map_variable_ref_expr: reuse name if already in lookup table
  Fix ToLoopyExpressionMapper for subscripted variables

Fix eval mapper cse recursion

See merge request !31

Caches for speedy bind

See merge request !30

Placate flake8 3.6

See merge request !28

Add Pytest/JUnit/Gitlab integration

See merge request !27

Preinstall pybind11 for pyopencl

See merge request !25

Use mpi4py.run in spawned MPI subprocessess

See merge request !24

This reverts merge request !23

Add PY_EXTRA_FLAGS="-m mpi4py.run" to help avoid stuck MPI-based CIs

See merge request !23

Fix one aspect of 1D support

See merge request !22

Fix env passing throug mpiexec

See merge request !21

Mpi communication

See merge request !11