Minor Performance issue fix within addTask() due to nested loop of DOM manipulation

Upon initilization, the amount of tasks (rows) in use determine how many
times GridEditor.prototype.addTask() will be called and once it's called
it would do another a each loop, which leads to piles of redundant loops
on stack, slowing down the performance in especially in IE9 if you have
a project with 200+ tasks. I didn't see practical use of this each loop
because the row index is always updated so I'd recommend comment it out.
Merge pull request #24 from LuoboTixS/master

Performance issue fix within addTask() due to nested loop of DOM manipulation