here is an example how working with typed payload objects could look
like. primarily for inspirational purposes ;) feel free to not merge or
edit or overhaul or whatever.

i just think the less manual string-fiddling, the better.

also, i reduced the gitignore of web-app/WEB-INF to web-app/WEB-INF/tld
because after checkout, i was not able to run-app b/c of missing
applicationContext.xml. so added grails-2.4.3 stock
applicationContext.xml and sitemesh.xml as well.