Add a log to labgrid places

[tksc]

We use the set-comment command to describe the current state of a place, e.g.:

lab1p1 -> "STM32 with linear, sdmux, usbgadget and configurable-bootpins" lab2p2 -> "i.mx8 eval board" lab3p2 -> "...."

As some of our setup often changes (due to $REASONS :) we thought about labgrid providing some kind of git backend to track the changes. On every invocation of "set-comment" the new comment should be appended to "the log" along with the current user, of course.

It could be a good idea that the comment matches the subject line of the git commit and a more verbose info could be shown by appending a -v option.

labgrid-client -p lab1p2 set-comment # Open editor to edit first commit msg

labgrid-client -p lab1p2 set-comment # Open editor to edit second commit msg

labgrid-client -p lab1p2 log # Shows 'git log' style output

labgrid-client -p lab1p2 show-comment -v # Displays the comment from labgrid-client places plus body of commit message

The last two commands of course could be replaced by using git itself.

If you think it's a good idea, maybe someone has some hints on how he would approach the implementation.

Looking forward for your feedback.

Best regards tsc