Support fullwidth characters

[waldyrious]

Running git fame in the a repository with authors whose names contain fullwidth characters (like Chinese, Japanese or Korean characters) results in incorrect alignment of the table.

For example, here's the (truncated) output for the https://github.com/oilshell/oil repo:

+-------------------------+-----------+---------+-------+---------------------+
| name                    | loc       | commits | files | distribution (%)    |
+-------------------------+-----------+---------+-------+---------------------+
| Andy Chu                | 1,643,208 | 3,802   | 4,302 | 99.1 / 96.0 / 100.3 |
| Andy C                  | 8,145     | 36      | 110   |  0.5 /  0.9 /  2.6  |
| granttrec               | 2,374     | 6       | 105   |  0.1 /  0.2 /  2.4  |
| :                       | :         | :       | :     |  :                  |
| myfreeweb               | 116       | 1       | 114   |  0.0 /  0.0 /  2.7  |
| Aleks Kamko             | 115       | 2       | 8     |  0.0 /  0.1 /  0.2  |
| Greg Price              | 103       | 4       | 4     |  0.0 /  0.1 /  0.1  |
| 조성빈                     | 73        | 1       | 3     |  0.0 /  0.0 /  0.1  |
| Yorwba                  | 72        | 8       | 10    |  0.0 /  0.2 /  0.2  |
| timetoplatypus          | 52        | 8       | 5     |  0.0 /  0.2 /  0.1  |
| Matt Singletary         | 51        | 1       | 2     |  0.0 /  0.0 /  0.0  |
| :                       | :         | :       | :     |  :                  |
| Brayden Banks           | 0         | 1       | 0     |  0.0 /  0.0 /  0.0  |
| Caroline Lin            | 0         | 1       | 0     |  0.0 /  0.0 /  0.0  |
| Chris West              | 0         | 1       | 0     |  0.0 /  0.0 /  0.0  |
+-------------------------+-----------+---------+-------+---------------------+