Add some usefull feature for freemarker

• Macro nest support
• TemplateModel modify
• Set param in a macro body
• Template extend support
• Access strut2 freemarker configuration in spring

you need add two directive into freemarker sharedVariable,liks this: public static void init(Configuration cfg) { cfg.setSharedVariable("param", new ParamDirective()); cfg.setSharedVariable("expose", new ExposeDirective()); }

esaily you can call DirectiveHelper.init(cfg);

example: ``` <#macro outer name="cici"> <@expose/> <#nested>

<#macro inner parent=""> <@expose parent="parent"/> ${parent.name}

<@outer><@inner/> ```

add <@expose/> to a macro body at the first line, then you can access parent macro context use parent variable

or set a param use:

<@param name="parent.name" value="ozn"/>

see testCase code for more info