Fix next bug
added "to" functionality
Filled in some code for the FilteredListTextBox
Changed mutators in TentativeTask to accept string parameters. Added skeleton for converting string dates to Date.
Tentative parser skeleton
Merge branch 'master' of https://github.com/cs2103aug2014-t11-1j/main into krystal
Set datestrings and timestrings into timeperiod and added timeperiod to task
TimePeriod class is now fully functional.
Merge remote-tracking branch 'origin/master' into yongkai