Create new time from existing time structure produces 0 when calculation duration

[Heribert17]

Environment:
OS: Windows 10
V: V 0.4.0 45e6e7d
I'm new to V and maybe I didn't read the documentation carefully enough.
While translating one of my programs from python to V I have to calculate a time difference. But I always got 0 as difference. So I made a small test program to check that.

module main

import time

fn main() {
	nowtime := time.now().local()
	newtime := time.new_time(time.Time{
		...nowtime
		hour: 10
		minute: 0
	})
	dump(nowtime)	// prints actual time
	dump(newtime)	// prints actual date and hour set to 10 and minutes to 0
	timedif := if newtime > nowtime { newtime - nowtime } else { nowtime - newtime }
	dump(timedif)	// prints 0ns
}

After analyzing the time.v and time.c.v files I found, that there is a field named unix. If that field isn't 0 the new_time function in time.c.v returns immediately. In the '-' function in operator.v the unix fields of both times are subtracted. So, as the new_time function doesn't set the unix field new, the returned value is always 0.

To fix that I had to modify the newtime setting in my program to:

 	newtime := time.new_time(time.Time{
		...nowtime
		hour: 10
		minute: 0
		unix: 0  // added to fix the problem
	})

I don't know if you would call it a bug or simply a missing hint in the documentation of the new_time function.

[spytheman]

I think we should change the docs of new_time to note about it. Thanks for the analysis.