1. cleanup trust.c (scale_Jg)
2. rewrite qrsolv
3. More/Sorensen method for mu calculation
4. better condition estimate for svd
5. fix subspace2D
6. Revisit h_fvv = 0.01 vs 0.02 (originally 0.01)
7. fdfvv test currently disabled in test_fdf.c - on MacOS, the lmaccel/box3d/fdfvv test fails
