Add check for MFEM_DIR to Makefile

[OCCA]Add zeroing of outvecs

Further work on Nek5000 BPs, added error checking to OpApply

[NEK][WIP] Modifying BPs

Add PETSc to prove-all target when PETSC_DIR is defined

[NEK][WIP] Modifying BPs

Upgrade PETSc bp1

[NEK][WIP] Convert bp1 and bp3

Fix t17-f issue IDd by Steven Roberts, temporarily restricting t17-f to 1d and 2d only

[MAGMA] Fix OP Setup

[MFEM] Remove print statements for prove-mfem

[NEK] bp1 and bp3 updated

Fixed minor MAGMA typo

[NEK] Starting to convert BPs

[PETSc][WIP] Modifying PETSc BP1, .okl need error fn updated, libceed install/petsc makefile issue

Documentation and style updates

Copy Ref updates to MAGMA

[MFEM] MFEM bp3 works

[MFEM] Convert MFEM bp1 to active passive

[tests] t20-qfunction.c revert debug traces

[mfem] qfunc to qdata field, but size does not match yet

[occa] removed Opencl __global in backends/occa/*okl

[occa] okl OpenCL hack to make all the tests run

[occa] qfunctions & operator cleanup

[occa] ex1 test running