Label: better speed/duration calculation.
Label: better speed/duration calculation.

This fix the speed calculation with slide_short and slide_bounce
animation. Previously the calc was right only for slide_long.

rvandegrift/elementary,tasn/elementary,tasn/elementary,rvandegrift/elementary,FlorentRevest/Elementary,rvandegrift/elementary,FlorentRevest/Elementary,FlorentRevest/Elementary,tasn/elementary,FlorentRevest/Elementary,tasn/elementary,rvandegrift/elementary,tasn/elementary