TODO items

[mgates3]

This is a loose collection of TODO items.

• [ ] Standardize order of layout, priority, queue. See PR #151 for comments.
• [ ] Rename tbsmPivots => tbsm_pivots
• [ ] Use tag_XYZ where appropriate. E.g., listBcast in work_trsmA.
• [ ] tileRecv can generate an OpenMP task. Is this desired? Do algorithms need to wait for the task? See comment in #122 and #161.
• [ ] Use tr_matrix in run_tests.py. See comment in #157.
• [ ] Address "fix gemmA on device" comment in test_her{k,2k}.cc. See comment in #157.
• [ ] Audit MPI tags to check for potential overflow; MPI only guarantees 32768; Intel and Cray 20-21 bits, not 32-bit values. See comment in #157.
• [ ] Add C generics, Fortran interfaces. See comment below.
• [ ] Add uplo or diag accessors in the C and Fortran APIs. See note in #152.
• [ ] Update c_api Python scripts to write blocks. See discussion in #152.
• [ ] Add user-level example of setting entries on the GPU. See user forum email "Is it possible to access matrix elemnts within Cuda?"