Autoscroll the last cursor when it inserts text

Normally, we don't autoscroll to a cursor when the buffer changes. But
this is a change caused by the cursor itself, so it makes sense to
keep it in view.

src/app/selection.coffee

@@ -154,6 +154,7 @@ class Selection
     wasReversed = @isReversed()
     text = @normalizeIndent(text, options) if options.normalizeIndent
     @clear()
+    @cursor.needsAutoscroll = @cursor.isLastCursor()
     newBufferRange = @editSession.buffer.change(oldBufferRange, text)
     if options.select
       @setBufferRange(newBufferRange, reverse: wasReversed)