When passing arrays between child processes with node's IPC machanism,
`instance of Array` will return false for the deserialized array, we
should use the reiable way of detecting Array provided by underscore.
Read this for more:
http://perfectionkills.com/instanceof-considered-harmful-or-how-to-write-a-robust-isarray/
This bug was found when moving spell-check to use ProcessTask, and the
wrong Range object was returned for the passed misspelling value.
Cursors and selections no longer need to handle buffer/display-buffer changes directly. They register anchors with the EditSession, and subscribe to changes in their position instead. This opens up the anchor facility for use by extensions that want to track the screen position of a point in the buffer as the buffer and display buffer change.
