Provide easy way out of track-changes

services/web/app/views/project/editor/track-changes.jade

@@ -8,9 +8,14 @@ div#trackChanges(ng-show="ui.view == 'track-changes'")
 					ng-class="buttonClass"
 					ng-click="startFreeTrial('track-changes')"
 				) #{translate("start_free_trial")}
+				|    
+				a.small(href, ng-click="toggleTrackChanges()") #{translate("cancel")}
 			p.small(ng-show="startedFreeTrial") #{translate("refresh_page_after_starting_free_trial")}
+
 		.message(ng-show="project.owner._id != user.id")
 			p #{translate("ask_proj_owner_to_upgrade_for_history")}
+			p
+				a.small(href, ng-click="toggleTrackChanges()") #{translate("cancel")}
 
 	aside.change-list(
 		ng-controller="TrackChangesListController"