XWIKI-6803: Upgrade to Groovy 1.8.1
XWIKI-6803: Upgrade to Groovy 1.8.1

xwiki/xwiki-platform,xwiki/xwiki-platform,xwiki/xwiki-platform,xwiki/xwiki-platform,pbondoer/xwiki-platform,pbondoer/xwiki-platform,pbondoer/xwiki-platform,pbondoer/xwiki-platform,xwiki/xwiki-platform,pbondoer/xwiki-platform