Details:
- Updated the level-3 performance graphs in docs/graphs with new Eigen
results, this time using a development version cloned from their git
mirror on March 27, 2019 (version 3.3.90). Performance is improved
over 3.3.7, though still noticeably short of BLIS/MKL in most cases.
- Very minor updates to docs/Performance.md and matlab scripts in
test/3/matlab.