Add an untagged filter in the projects list.

services/web/app/views/project/list/side-bar.pug

@@ -79,6 +79,11 @@
 					li
 						a(href, ng-click="deleteTag(tag)", stop-propagation="click")
 							| #{translate("delete")}
+		li.tag(
+			ng-if="tags.length",
+			ng-cloak,
+			ng-click="selectUntagged()"
+		) uncategorized
 		li(ng-cloak)
 			a.tag(href, ng-click="openNewTagModal()")
 				i.fa.fa-fw.fa-plus

services/web/public/coffee/main/project-list/project-list.coffee

@@ -113,6 +113,10 @@ define [
 				if $scope.filter == "tag" and selectedTag? and project.id not in selectedTag.project_ids
 					visible = false
 
+				# Hide tagged projects if we only want to see the uncategorized ones
+				if $scope.filter == "untagged" and project.tags?
+					visible = false
+
 				# Hide projects we own if we only want to see shared projects
 				if $scope.filter == "shared" and project.accessLevel == "owner"
 					visible = false

services/web/public/coffee/main/project-list/tag-controllers.coffee

@@ -15,7 +15,11 @@ define [
 			$scope._clearTags()
 			tag.selected = true
 			$scope.setFilter("tag")
-		
+
+		$scope.selectUntagged = () ->
+			$scope._clearTags()
+			$scope.setFilter("untagged")
+
 		$scope.deleteTag = (tag) ->
 			modalInstance = $modal.open(
 				templateUrl: "deleteTagModalTemplate"