allow ace to scoll off screen

services/web/public/coffee/ide/editor/directives/aceEditor.coffee

@@ -163,12 +163,15 @@ define [
 				scope.$watch "readOnly", (value) ->
 					editor.setReadOnly !!value
 
+				editor.setOption("scrollPastEnd", true)
+
 				resetSession = () ->
 					session = editor.getSession()
 					session.setUseWrapMode(true)
 					session.setMode("ace/mode/latex")
 					session.setAnnotations scope.annotations
 
+
 				updateCount = 0
 				onChange = () ->
 					updateCount++