Store slot time in Timeslot object

This will allow me to check against the head to head times when
scheduling.

task #287: schedule all finalists at once, considering head-to-head
schedule [sf#268] 
http://github.com/jpschewe/fll-sw/issues/issue/287
Store head to head time information in the finalist scheduling app

Once I know which teams are in which playoff division I can then exclude
the times that they are in playoffs.

task #287: schedule all finalists at once, considering head-to-head
schedule [sf#268] 
http://github.com/jpschewe/fll-sw/issues/issue/287
Schedule all finalists in the same division at once

Previously the scheduling was done by playoff division OR event
division. This got quite confusing for the head judge.

Fixes #287.

task #287: schedule all finalists at once, considering head-to-head
schedule [sf#268] 
http://github.com/jpschewe/fll-sw/issues/issue/287
Merge branch 'task.287.schedule-all-finalists'