Upgrade to FreeMarker 2.3.28 and Netty 4.1.23

build.gradle

@@ -42,7 +42,7 @@ configure(allprojects) { project ->
 	version = qualifyVersionIfNecessary(version)
 
 	ext.aspectjVersion       = "1.8.13"
-	ext.freemarkerVersion    = "2.3.27-incubating"
+	ext.freemarkerVersion    = "2.3.28"
 	ext.groovyVersion        = "2.4.15"
 	ext.hsqldbVersion        = "2.4.0"
 	ext.jackson2Version      = "2.9.5"
@@ -52,7 +52,7 @@ configure(allprojects) { project ->
 	ext.junitVintageVersion  = "5.1.0"
 	ext.kotlinVersion        = "1.2.31"
 	ext.log4jVersion         = "2.11.0"
-	ext.nettyVersion         = "4.1.22.Final"
+	ext.nettyVersion         = "4.1.23.Final"
 	ext.reactorVersion       = "Bismuth-SR8"
 	ext.rxjavaVersion        = "1.3.8"
 	ext.rxjavaAdapterVersion = "1.2.1"