Added lines to write the edited task to the file
Added a case to do something with the command type HELP
Wrote a new message for a list of commands for the user
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:
  Added "Complete" as a printable attribute
  Finished the delete functionality.