comment calcduration: 1) allow independent choice of start, end, duration.and 2) wrong calculation..

in projectdesigner: ..comment calcduration: 1) allow independent choice of start, end, duration  2) it calculates wrong, anyway

bug id 1410:  
1) on add task: when displaying line,  duration is set to -3 hours
2) on changing task end date by 2 days, duration is increased 8 hours (maybe working hours? but then it should be 16 hours).

this pull has commented the js function away. I think it is undesirable to force end=start + duration, and it calculates wrong, anyway.

Thus: start, end and duration can be set independently. This probably happens more often than forcing end = start + duration. (like: between today and Friday, I work 3 hours on the task

Klaus