Added suspend resume functionality

[mandeepbrar]

Suspend resume functionality on a watcher. Used when developer wants to listen to change events on a folder, but makes changes to the watched folder itself in case of the changes.

developer can then write

select {
			case event := <-watcher.Event:
				{
                                     watcher.Suspend()
                                     ... do changes on the watched folder and not generate unnecessary events because of developers processing
                                    watcher.Resume()
                               }
}