Uses Jekyll instead Maven to generate site

git-svn-id: https://svn.apache.org/repos/asf/struts/site@1569205 13f79535-47bb-0310-9956-ffa450edef68
Merge all from jekyll-powered at 1569207 (reintegration)

git-svn-id: https://svn.apache.org/repos/asf/struts/site@1569208 13f79535-47bb-0310-9956-ffa450edef68
Branch integrated into trunk

git-svn-id: https://svn.apache.org/repos/asf/struts/site@1569211 13f79535-47bb-0310-9956-ffa450edef68