add print representation of Lookup object

[mschweikardt]

Printing a Lookup object (print(NCH)) will show a reasonable print representation:

+----------+-------------+-----------+----------+
| Variable |     Size    |    Min    |   Max    |
+----------+-------------+-----------+----------+
|    ID    | 32x73x73x11 | -0.00e+00 | 3.19e-03 |
|    VT    | 32x73x73x11 |  3.79e-01 | 7.20e-01 |
|    GM    | 32x73x73x11 |  0.00e+00 | 2.92e-03 |
|   GMB    | 32x73x73x11 |  0.00e+00 | 7.32e-04 |
|   GDS    | 32x73x73x11 |  4.72e-16 | 1.08e-02 |
|   CGG    | 32x73x73x11 |  6.08e-15 | 8.80e-14 |
|   CGS    | 32x73x73x11 |  2.45e-15 | 7.09e-14 |
|   CGD    | 32x73x73x11 |  2.26e-15 | 4.25e-14 |
|   CGB    | 32x73x73x11 | -2.40e-16 | 2.41e-14 |
|   CDD    | 32x73x73x11 |  5.39e-15 | 1.20e-13 |
|   CSS    | 32x73x73x11 |  6.03e-15 | 8.02e-14 |
|   STH    | 32x73x73x11 |  9.96e-34 | 1.79e-22 |
|   SFL    | 32x73x73x11 |  0.00e+00 | 4.82e-15 |
|   INFO   | 32x73x73x11 |    N/A    |   N/A    |
|  CORNER  | 32x73x73x11 |    N/A    |   N/A    |
|   TEMP   |      1      |  3.00e+02 | 3.00e+02 |
|   VGS    |      73     |  0.00e+00 | 1.80e+00 |
|   VDS    |      73     |  0.00e+00 | 1.80e+00 |
|   VSB    |      11     |  0.00e+00 | 1.00e+00 |
|    L     |      32     |  1.80e-01 | 2.00e+00 |
|    W     |      1      |  5.00e+00 | 5.00e+00 |
|  NFING   |      1      |  1.00e+00 | 1.00e+00 |
+----------+-------------+-----------+----------+