show rate limit message when compiled too much

services/web/app/views/project/editor/pdf.pug

@@ -328,6 +328,10 @@ div.full-size.pdf(ng-controller="PdfController")
 			.alert.alert-danger(ng-show="pdf.compileTerminated")
 				strong #{translate("terminated")}. 
 				span #{translate("compile_terminated_by_user")}
+			
+			.alert.alert-danger(ng-show="pdf.rateLimited")
+				strong #{translate("pdf_compile_rate_limit_hit")} 
+				span #{translate("project_flagged_too_many_compiles")}
 
 			.alert.alert-danger(ng-show="pdf.timedout")
 				p

services/web/public/coffee/ide/pdf/controllers/PdfController.coffee

@@ -388,7 +388,9 @@ define [
 					$scope.pdf.view = "pdf"
 					$scope.pdf.compiling = false
 					parseCompileResponse(data)
-				.error () ->
+				.error (err, status) ->
+					if status = 429
+						$scope.pdf.rateLimited = true
 					$scope.pdf.compiling = false
 					$scope.pdf.renderingError = false
 					$scope.pdf.error = true