changed a return string message in search. updated tab completion to recognise capital letters.
Merge branch 'master' of https://github.com/cs2103aug2014-T13-2J/main

# By Nee Si Yao
# Via Nee Si Yao
* 'master' of https://github.com/cs2103aug2014-T13-2J/main:
  Implement undo for GoogleCalendar.
  Remove unused library imports in UI.