Changed all the initialisations to null and wrote a new method for checking duplication of tasks (By name only for now)
Merge branch 'master' of https://github.com/cs2103aug2014-t7-2/main

# By Natalie Rawle
# Via Natalie Rawle
* 'master' of https://github.com/cs2103aug2014-t7-2/main:
  Made a few changes to fix bugs.