Added the authors for the methods.
Reformatted the ezCMessages for the help list
Added a class description for Edit()
Added two new enums, DATE and TIME for HELP_KEY in subcommands
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:
  enabled Date in appropriate commands
Wrote message for Undo-ing Repeat()
Changed subcommand type to a switch-case for isHelpType()
Added cases for switch statements "date" and "time" for Help()
Added throws exception for makeCommand
Added more exception throws
Added date and time for help
Added more messages for Date Help and Time Help
Merge branch 'master' of https://github.com/cs2103aug2014-t7-2/main

# By Yui Wei
# Via Yui Wei
* 'master' of https://github.com/cs2103aug2014-t7-2/main:
  no message