Changes to these files
- Logic.java  is able to cater for AdD, EDIT, delete, etc and also able to cater for short commands like A, DEL, DONE, s, u, e
- ToDoView is able to cater shorter commands like done, c.
- CommandUtil -> removes .toLowerCase() so to cater for different form of command
- add new test cases for shorter commands.
Merge pull request #111 from cs2103aug2014-t17-3j/Issue_#108_-_shorter_commands

Issue #108 - Shorter Command