modified add -impt -trivial
Fixed the equals() method in Task

consider different cases
Fixed the bugs in the constructor
Fixed the bug inside UndoManager
dummy search added
Merge pull request #65 from cs2103aug2014-w15-3J/parser

Merge Master with Parser
Merge pull request #66 from cs2103aug2014-w15-3J/Logic

Merge Master with Logic
Merge pull request #67 from cs2103aug2014-w15-3J/master

Merge Logic with Master