delete unused methods
implement delete(TaskUIFormat) method in ZombieStorage to support delete
tasks with same name, tag or location; and delete tasks at certain time
slot.
add mulitple Task delete functions for tag, name, location, time
Merge branch 'ZombieStorage' into mainlogic
edit false descriptors in delete commands
fixed *noob1 and *friday friday bugs
Merge remote-tracking branch 'origin/mainlogic'

Conflicts:
	src/interpreter/CommandSearchTag.java
	src/interpreter/Interpreter.java