Clear highlighted word manager on session change

services/web/public/coffee/ide/editor/directives/aceEditor/spell-check/HighlightedWordManager.coffee

@@ -12,6 +12,9 @@ define [
 
 	class HighlightedWordManager
 		constructor: (@editor) ->
+			@reset()
+		
+		reset: () ->
 			@highlights = rows: []
 
 		addHighlight: (highlight) ->

services/web/public/coffee/ide/editor/directives/aceEditor/spell-check/SpellCheckManager.coffee

@@ -22,6 +22,8 @@ define [
 				@closeContextMenu()
 
 			@editor.on "changeSession", (e) =>
+				@highlightedWordManager.reset()
+
 				if @$scope.spellCheckEnabled and @$scope.spellCheckLanguage and @$scope.spellCheckLanguage != ""
 					@runSpellCheckSoon(200)