Add regularization and number of backtracks to diagnostics

[calcmogul]

Examples:

iter   time (ms)      error          cost       infeasibility  reg   backtracks
===============================================================================
   0       3.832   5.279228e+02   2.613729e+01   5.940363e+03  10⁻⁴           5
   1       3.826   1.309315e+03   3.904672e+01   5.913762e+03  10⁻⁴           7
   2       3.624   2.908785e+01   6.829736e+01   5.873628e+03  10⁻⁴           7
   3       3.812   2.375783e+02   7.304661e+01   5.871579e+03   1            11
   4       3.889   2.134911e+03   8.013176e+01   5.864523e+03   1             9
   5       4.242   8.779660e+03   9.372899e+01   5.850240e+03   1             8
   6       3.649   1.020610e+04   1.161645e+02   5.830460e+03  10             8
   7       6.833   1.120983e+04   1.195454e+02   5.827803e+03  10            11
   8       4.110   5.651185e+03   1.318368e+02   5.818040e+03  10²            9
   9       3.799   4.857091e+03   1.456865e+02   5.802622e+03  10³            8
  10       3.714   2.335885e+04   1.511013e+02   5.793224e+03  10³            9
  11       3.557   7.149313e+03   1.572301e+02   5.784683e+03  10³            9
  12       3.815   4.958424e+04   2.470276e+02   5.629232e+03  10⁴            5
  13       3.669   3.003325e+04   3.419977e+02   5.501672e+03  10⁴            5
  14       3.572   2.434288e+04   3.422190e+02   5.501421e+03  10³           14
  15       3.924   4.215715e+04   1.074048e+03   4.777672e+03  10⁴            3
  16       4.551   2.005596e+04   3.105042e+03   3.628277e+03  10⁴            2
  17       3.758   1.770806e+05   3.808402e+03   3.339475e+03  10³            3
  18       3.809   2.394209e+04   7.134606e+03   2.121278e+03  10⁴            1
  19       3.588   2.813119e+04   7.164151e+03   2.112274e+03  10⁴            7
iter   time (ms)      error          cost       infeasibility  reg   backtracks
===============================================================================
  20      21.466   2.826093e+04   7.164151e+03   2.112134e+03  10⁴           13
  21       4.764   2.567895e+04   7.164154e+03   2.112133e+03  10³           21
  22       3.811   2.742097e+04   7.164916e+03   2.111872e+03  10⁴           12
  23       3.678   3.261816e+03   7.444860e+03   2.022223e+03  10⁴            4
  24       3.830   2.502083e+04   7.505754e+03   2.004529e+03  10⁴            6
iter   time (ms)      error          cost       infeasibility  reg   backtracks
===============================================================================
   0r     16.724   2.690442e+04  -6.433055e+09   6.440839e+06   0             9
   1r     16.102   2.688440e+04  -6.428267e+09   6.436044e+06   0            10
   2r     15.655   2.476523e+04  -5.921558e+09   5.928723e+06   0             3
   3r     15.605   2.112236e+04  -5.050519e+09   5.056632e+06   0             2

iter   time (ms)      error          cost       infeasibility  reg   backtracks
===============================================================================
   0       2.430   1.771198e+05   5.227495e+01   1.282972e+02  10⁻⁴           0
   1       2.722   4.466788e+03   2.363619e+01   2.132855e+01  10⁴            0
   2       2.392   8.546946e+02   2.561887e+01   3.128966e+00  10⁵            0
   3       2.662   2.470021e+04   2.780689e+00   1.573462e+01  10⁶           11
   4       2.174   1.836587e+04   8.117697e+00   9.060743e+00  10⁶            0
   5       2.131   3.900276e+02   9.675301e+00   6.205808e+00  10⁶            0
   6       3.036   5.709649e+04   7.067670e+00   2.081428e+01  10⁷            0
   7      20.013   2.457931e+05   7.923420e+00   1.640462e+01  10⁷            7
   8       2.380   7.171578e+04   8.007898e+00   1.294796e+01  10⁷            0
   9       2.141   3.308662e+04   8.147714e+00   7.381907e+00  10⁷            0