Accept an object object to make the component more general
Revert "Removed Exception from `displayResult(Result result);`"

This reverts commit d20b42b565a0d95fe5b59caf6908570e2ab8bdc4.
Removed Exception from displayResult method.
changed unitTest for Parser
Revert "Removed Exception from displayResult method."

This reverts commit 01ecf0832cc042069eb7f76e7dfda8186d015188.
Removed exception from desiplayResult method
Merge branch 'ui/victor' into parser/Victor
Merge remote-tracking branch 'origin/controller/sharon' into logic/wenhao
Merge remote-tracking branch 'origin/parser/Victor' into logic/wenhao
Undo return a result now.
accept command as argument in logic
change default start/end time to null
Merge commit '368862f25be5ae3e729474437d972afe7d378bb3' into ui/victor
showhelp argument change to command
Included priority in showing a task's details
Added unit tests for OutputImpl
Refined date parsing
#29
Merge remote-tracking branch 'origin/parser/Victor' into controller/sharon
Merge remote-tracking branch 'origin/ui/victor' into controller/sharon
Merge remote-tracking branch 'origin/logic/wenhao' into controller/sharon