Fix object array vectorization in interior_trace_pair

Switch install docs to miniforge

See merge request !89

Dofarray not ndarray subclass

Fix incorrect dtypes being used for cache keys in map_elementwise_linear and map_ref_face_mass_operator

Loo py to loopy

Doc unit normal

Document unit normal getter.

Reinstate https://github.com/inducer/grudge/pull/19

Revert https://github.com/inducer/grudge/pull/19

Switch pytools.log -> logpyle, add to requirements.txt

See merge request !88

Add caching to batched diff

This reverts commit c3aaac67.

Mpi fixes

See merge request !86