Store the user input command string in the command object
Added search command
Added status param
Change end date to due date
Change more end date to due date
Command Parser now throw invalid command message
removed setCompleted method
Merge branch 'xy-command-commandString' of https://github.com/cs2103aug2014-w13-4j/main

Conflicts:
	src/command/CommandParser.java
Fix bug in task test
Merge branch 'chuyu-storage' of github.com:cs2103aug2014-w13-4j/main into pn-chuyu-logic-storage-merge
Merge branch 'chuyu-storage' of github.com:cs2103aug2014-w13-4j/main into pn-chuyu-logic-storage-merge
check whether storage is null before searching
Modified DateParser to convert string to calendar object, and wrote a test for it
Merge branch 'chuyu-storage' of github.com:cs2103aug2014-w13-4j/main into pn-chuyu-logic-storage-merge
Allowed adding of date in logic
Merge branch 'pn-chuyu-logic-storage-merge' of github.com:cs2103aug2014-w13-4j/main
modify names:
Merge branch 'master' of https://github.com/cs2103aug2014-w13-4j/main into chuyu-storage
minor changes for format and small bugs