Add datetime to logs

[kslcsdalsadg]

It adds current datetime to logs

[Weidav]

I'm glad to see this pull-request, I was looking for exactly this and planned to implement this on my on.

I would suggest to either remove .strftime() or change it to %Y-%m-%d .... This seems to be the standard and avoid confusion for users in America.

[cotton105]

I requested #180 which I think complements this nicely on the GUI side.

[QbikEdge]

#173 should also be checked. It alters also the output.