Add the JSON plugin to the basic game template

BasicGameTemplate/nbproject/project.properties

@@ -43,7 +43,8 @@ javac.classpath=\
     ${libs.jme3-effects.classpath}:\
     ${libs.jme3-terrain.classpath}:\
     ${libs.jme3-jbullet.classpath}:\
-    ${libs.jme3-awt-dialogs.classpath}
+    ${libs.jme3-awt-dialogs.classpath}:\
+    ${libs.jme3-plugins-json.classpath}
 # Space-separated list of extra javac options
 javac.compilerargs=
 javac.deprecation=false