Attempt to solve issue #126

Problem: if user deliberately sets end time ahead of start time by less than one day, input parser will try to add one more day to end time to make start time < end time.

Example from 1p 09/11 to 2p 08/11
Merge branch 'master' of https://github.com/cs2103aug2014-w10-4j/main
Move checking of start time and end time to date parser