Add directive based on jQuery animation API.

services/web/public/coffee/ide/review-panel/directives/reviewPanelCollapseHeight.coffee

@@ -0,0 +1,15 @@
+define [
+	"base"
+], (App) ->
+	App.directive "reviewPanelCollapseHeight", ($parse) ->
+		return {
+			restrict: "A",
+			link: (scope, element, attrs) ->
+				scope.$watch (() -> $parse(attrs.reviewPanelCollapseHeight)(scope)), (shouldCollapse) ->
+					neededHeight = element.prop("scrollHeight")
+					if neededHeight > 0
+						if shouldCollapse
+							element.animate { height: 0 }, 150
+						else
+							element.animate { height: neededHeight }, 150
+		}