Display driver version in the header

[wookayin]

Introduce --header option that specifies whether each of {host,time,driver} will be displayed in the header. Display driver version in the header:

e.g.

$ gpustat        # by default, {host,time} are only shown
$ gpustat --header host,time,driver

which prints:

workstation          Tue Oct 30 20:50:35 2018  396.54
[0] TITAN Xp         | 41'C,   0 % |  4479 / 12196 MB | user(4469M)
[1] TITAN Xp         | 38'C, 100 % |  4479 / 12196 MB | user(4469M)

• What would be the best format?
• Should we make it configurable (see Fully configurable output format #51)?

[wookayin]

We will not include a configuration point for now. Driver version will be shown by default.

Closed by caba47e.