Pass the test case
Change a little bit in ZombieTaskCommandHandler to solve the update
problem for task with two deadlines
Merge branch 'ZombieStorage' into mainlogic
implement search functions
delete all useless file
implement undo method
partial implementation of
-	update help command
-	add clash warning
-	delete depreciated methods
-	add location
Merge branch 'ZombieStorage' into mainlogic

Conflicts:
	ZombieLog.0.0.txt
	ZombieLog.1.0.txt
	ZombieLog.1.1.txt
	ZombieLog.2.0.txt
	ZombieLog.3.0.txt
	ZombieStorage.txt
update viewagenda and taskclash functions