Feature Request: Round Logging

[mmellaa]

For simplicity, we have agreed with our customer to report time rounded to 15 min.
For example: 15min, 30min, 45min, 1h, 1h 15min, etc.
That way, reports show: 0,25h ; 0,5h ; 0,75h and so on.

So i would love to log time to more significative numbers, like 5min, 10min, 15min or any.

[mmellaa]

I found later that this is same request as #129