update_start_time(): Allow for moving an item
update_start_time(): Allow for moving an item

Add a parameter that specifies whether the duration should be updated
when updating the start time of an item.

Signed-off-by: Lukas Fleischer <af90e31281d8305af43dc616c5aaca3c7165f8a7@cryptocrack.de>

lfos/calcurse,lfos/calcurse,lfos/calcurse