Added skeleton for rootlayout and a menu bar. Changed css to incorporate this.
Playing around with different menu bar placing.
Fixed bug with Clear command feedback.
Added sort by alpha
Fixed bug in parser

Dates are no longer valid if endDate > startDate
Added sort by position
Merge remote-tracking branch 'origin/jiashun'

Conflicts:
	src/parser/InputParser.java
Added menu bar to overall view instead of root layout. Changed css to suit.
Changed blue theme to be royal blue instead of slate blue. (Cos slate blue looks purple)
BUGS LIFE
MOAR BUGS

LOL
Added green and red themes. Refactored darkTheme
Added popup functionality. (type popup to test) Edited css files to suit.
1.modified the modeltask class to add in the deadline attributes
2.modified sort method in logic. in specific, the sort by date method
3.added comparator for sorting by date

now program can sort by date
Merge remote-tracking branch 'origin/yongkai'
Merge remote-tracking branch 'origin/krystal'

Conflicts:
	src/gui/view/RootLayout.fxml
Added functionality to menubar. Allow user to change themes from menubar.
Changed edit menu to themes menu.
Added ThemeMenuHandler to handle selection changing.
Fixed duplicate position on deletion of task and undo-ing
Merge remote-tracking branch 'origin/krystal'
modified editlistener. now the list is updated correctly. However, it doesnt support search list yet
Merge remote-tracking branch 'origin/yongkai'