Update .vcxproj

Should work when we pull from github without having to replace the
.vcxproj from dropbox now. :smiley:
Undo and Redo function :thumbsup:

Single level undo and redo functionality added
Merge pull request #49 from cs2103aug2014-t14-3c/undo-redo-function

Undo and Redo function :thumbsup:
Merge remote-tracking branch 'origin/master' into new_feature_edit_class